Lateral flow assay with controlled conjugate time and controlled flow time

ABSTRACT

A lateral flow assay device comprising a conjugate pad for receiving a quantity of fluid; and a membrane comprising a test line for determining whether the fluid comprises a target analyte. In a first state of the lateral flow assay device, the lateral flow assay device is configured with a removable gap between the conjugate pad and the membrane which is substantially filled with air and prevents the fluid from flowing from the conjugate pad into the membrane. In a second state of the lateral flow assay device, the removable gap is removed from between the conjugate pad and the membrane causing the conjugate pad to come in contact with the membrane, allowing the fluid to flow from the conjugate pad into the membrane and the test line by capillary action.

CLAIM OF BENEFIT TO PRIOR APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/986,175, filed on Aug. 5, 2020. U.S. patent application Ser.No. 16/986,175 is a continuation of U.S. patent application Ser. No.16/698,788, filed on Nov. 27, 2019, issued as U.S. Pat. No. 10,739,297.U.S. patent application Ser. No. 16/698,788 claims the benefit of U.S.Provisional Patent Application Ser. No. 62/772,525, filed on Nov. 28,2018. The contents of U.S. patent application Ser. No. 16/986,175, U.S.patent application Ser. No. 16/698,788, issued as U.S. Pat. No.10,739,297, and Provisional Patent Application 62/772,525 are herebyincorporated by reference.

BACKGROUND

Lateral flow assays (LFAs) are devices that are used to detect thepresence (or absence) of a target analyte in a sample fluid without theneed for specialized equipment. The lateral flow assays are widely usedfor medical diagnostics for point of care testing, home testing, orlaboratory use.

A lateral flow assay typically includes a series of capillary pads fortransporting fluid. A sandwich assay format may be used for detectinganalytes that have at least two binding sites to bind to an antibody. Asample pad is used to receive a quantity of fluid (referred to as thesample fluid) and transport the sample fluid to an adjacent conjugatepad. The conjugate pad contains a solubilized antibody labeled with adetector such as colloidal gold nanoparticles. The antibody is specificto a certain analyte which is the target of interest in the samplefluid. As the sample fluid flows through the conjugate pad, the analyte(if any) in the sample fluid binds with the labeled antibody on theconjugate pad and forms an immunocomplex.

The immunocomplex then flows from the conjugate pad into an adjacentmembrane (or membrane pad). The membrane has a test area, or test line,that contains an immobilized unlabeled antibody. As the immunocomplexmoves over the test area, the immunocomplex binds with the immobilizedantibody on the test area, resulting in a colored test line. When thesample fluid does not include the target analyte, no immunocomplex isformed on the conjugate pad and no immunocomplex binds with theimmobilized antibody on the test area. As a result, the test line doesnot change color.

A lateral flow assay may also include a control line in the membrane. Ina sandwich assay format, the control line may contain an immobilizedantibody that binds to the free antibodies labeled with the detectorresulting in a colored control line, which confirms that the test hasoperated correctly regardless of whether or not the target analyte hasbeen present in the sample.

A competitive assay format may be used for detecting analytes thatcannot simultaneously bind to two antibodies. The sample pad and theconjugate pad in a competitive assay format are similar to the samplepad and the conjugate pad in the sandwich assay format. In thecompetitive assay format, the test line contains immobilized analytemolecules.

If the sample liquid does not contain the analyte, the labeled antibodyflows from the conjugate pad into the test line and binds to the analyteat the test line, resulting in a colored test line that indicates thelack of the target analyte in the sample liquid. If, on the other hand,the target analyte is present in the sample liquid, the analyte binds tothe labeled antibodies on the conjugate pad and prevents the labeledantibody to bind to the analyte at the test line, resulting in the lackof color on the test line. In a competitive assay format, the controlline may contain an immobilized analyte that binds to the freeantibodies labeled with the detector resulting in a colored controlline, which confirms that the test has operated correctly regardless ofwhether or not the target analyte has been present in the sample.

BRIEF DESCRIPTION OF THE DRAWINGS

The various embodiments of the present lateral flow assay withcontrolled conjugate time and controlled flow time now will be discussedin detail with an emphasis on highlighting the advantageous features.These embodiments depict the novel and non-obvious lateral flow assaywith controlled conjugate time and controlled flow time shown in theaccompanying drawings, which are for illustrative purposes only. Thesedrawings include the following figures, in which like numerals indicatelike parts:

FIG. 1 is an upper front perspective view of one example embodiment of aportion of a lateral flow assay device, according to various aspects ofthe present disclosure;

FIG. 2 is an upper front perspective view of one example embodiment of aportion of a lateral flow assay device showing a cross section of thelateral flow assay device's housing, according to various aspects of thepresent disclosure;

FIG. 3 is an upper front perspective view of one example embodiment of aportion of a lateral flow assay device showing the removal of thebarrier, according to various aspects of the present disclosure;

FIG. 4 is an upper front perspective of one example embodiment of aphysical barrier with a piece of magnet attached to it, according tovarious aspects of the present disclosure;

FIG. 5 is a functional block diagram illustrating one example embodimentof a linear actuator that may be used for pulling out the physicalbarrier of a lateral flow assay device, according to various aspects ofthe present disclosure;

FIG. 6 is a functional block diagram illustrating one example embodimentof a solenoid that may be used for pulling out the physical barrier of alateral flow assay device, according to various aspects of the presentdisclosure;

FIG. 7 is a functional block diagram illustrating one example embodimentof an electromagnet that may be used for pulling out the physicalbarrier of a lateral flow assay device, according to various aspects ofthe present disclosure;

FIG. 8 is an upper front perspective of one example embodiment of aphysical barrier that includes a hole, according to various aspects ofthe present disclosure;

FIG. 9 is a functional block diagram illustrating one example embodimentof the linear moving shaft of FIG. 5 with a hook that is used forpulling out the physical barrier of a lateral flow assay device,according to various aspects of the present disclosure;

FIG. 10 is an upper front perspective of one example embodiment of aphysical barrier that includes a groove for pulling out the physicalbarrier of a lateral flow assay device, according to various aspects ofthe present disclosure;

FIG. 11 is a flowchart illustrating an example process for pulling out abarrier that separates the labeling and capture zones of a lateral flowassay device, according to various aspects of the present disclosure;

FIG. 12 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device that includes a permanent gapin the backing card and/or the cartridge bed to prevent the leaking ofthe fluid material from under the conjugate pad into the membrane whilethe barrier is in place, according to various aspects of the presentdisclosure;

FIG. 13 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device with a permanent gap in thebacking card and/or the cartridge bed, showing the removal of thebarrier, according to various aspects of the present disclosure;

FIG. 14 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device showing a cartridge inside thedevice's housing, according to various aspects of the presentdisclosure;

FIG. 15 is a front elevation view of the lateral flow assay device ofFIG. 14, according to various aspects of the present disclosure;

FIG. 16 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device with multiple barrier zones,according to various aspects of the present disclosure;

FIG. 17 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device showing a cross section of thelateral flow assay device's housing, according to various aspects of thepresent disclosure;

FIG. 18 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device showing the removal of multiplebarriers, according to various aspects of the present disclosure;

FIG. 19 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device that includes one or morepermanent gaps in the backing card and/or the cartridge bed to preventthe leaking of the fluid material while the corresponding barrier(s)is/are in place, according to various aspects of the present disclosure;

FIG. 20 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device that has a gap separating thelabelling zone and the capture zone, according to various aspects of thepresent disclosure;

FIG. 21 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device showing a cross section of thelateral flow assay device's housing before and after removing a gapbetween the labeling zone and the capture zone, according to variousaspects of the present disclosure;

FIG. 22 is a top elevational view of the housing of the lateral flowassay device of FIG. 21, according to various aspects of the presentdisclosure;

FIG. 23 is a front elevational view of one example embodiment of aportion of a lateral flow assay device that may use one or more posts orpillars to create a removable gap between the conjugate pad and themembrane, according to various aspects of the present disclosure;

FIG. 24 is a top elevational view of one example embodiment of thelateral flow assay device of FIG. 23, according to various aspects ofthe present disclosure;

FIG. 25 is a front elevational view of one example embodiment of aportion of a lateral flow assay device after a gap between the conjugatepad and the membrane is removed, according to various aspects of thepresent disclosure;

FIG. 26 is a flowchart illustrating an example process for removing agap that separates the labeling and capture zones of a lateral flowassay device, according to various aspects of the present disclosure;

FIG. 27 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device with multiple gaps separatingdifferent components of the lateral flow assay device, according tovarious aspects of the present disclosure;

FIG. 28 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device showing a cross section of thelateral flow assay device's housing before and after removing multiplegaps, according to various aspects of the present disclosure;

FIG. 29 is a front elevational view of one example embodiment of aportion of a lateral flow assay device that may use multiple posts orpillars to create removable gaps between different components of thelateral flow assay device, according to various aspects of the presentdisclosure;

FIG. 30 is a top elevational view of one example embodiment of thelateral flow assay device of FIG. 29, according to various aspects ofthe present disclosure;

FIG. 31 is a front elevational view of one example embodiment of aportion of a lateral flow assay device after several gaps are removedbetween different components of the lateral flow assay device, accordingto various aspects of the present disclosure;

FIG. 32 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that removes gaps by a spring mechanism,according to various aspects of the present disclosure;

FIG. 33 is a functional block diagram illustrating one exampleembodiment of the lateral flow assay device of FIG. 32, according tovarious aspects of the present disclosure;

FIG. 34 illustrates an example of a number of curves generated for aparticular membrane paper material for a range of connection time anddisconnection time of the conjugate pad and the membrane, according tovarious aspects of the present disclosure;

FIG. 35 illustrates an example of selecting the connection anddisconnection times of the conjugate and membrane pads for a specifiedflow time, according to various aspects of the present disclosure;

FIG. 36 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by a spring mechanism and an electromagnet, accordingto various aspects of the present disclosure;

FIG. 37 is a functional block diagram illustrating one exampleembodiment of the lateral flow assay device of FIG. 36, according tovarious aspects of the present disclosure;

FIG. 38 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by a piezoelectric actuator, according to variousaspects of the present disclosure;

FIG. 39 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by magnets and electromagnets, according to variousaspects of the present disclosure;

FIG. 40 is a functional block diagram illustrating one exampleembodiment of the lateral flow assay device of FIG. 39, according tovarious aspects of the present disclosure;

FIG. 41 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by magnets and electromagnets that are positioned overthe lateral flow assay device's housing, according to various aspects ofthe present disclosure;

FIG. 42 is a functional block diagram illustrating one exampleembodiment of the lateral flow assay device of FIG. 41, according tovarious aspects of the present disclosure;

FIG. 43 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by moving a portion of the membrane with a springmechanism, according to various aspects of the present disclosure;

FIG. 44 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by a piezoelectric actuator that moves a portion of themembrane, according to various aspects of the present disclosure;

FIG. 45 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by a spring mechanism and an electromagnet that moves aportion of the membrane, according to various aspects of the presentdisclosure;

FIG. 46 is a front elevation view of one example embodiment of a portionof a lateral flow assay device that that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by a magnet and an electromagnet that moves a portionof the membrane, according to various aspects of the present disclosure;and

FIG. 47 conceptually illustrates an electronic system with which someembodiments of the invention are implemented.

DETAILED DESCRIPTION

One aspect of the present embodiments includes the realization that someanalytes may require a long binding time, also referred to as conjugatetime, in order to bind with the labeled antibody on the conjugate pad toform an immunocomplex. It may also be necessary to have a long bindingtime for the immunocomplex that flows onto the test/control membrane padto bind to the test line and control line on the membrane pad. The timeit takes for the immunocomplex fluid to flow from one end of themembrane pad to the other end is referred to as flow time.

It may also be desirable to precisely control the conjugate time forcertain types of tests. In a lateral flow assay, the fluid flowslaterally from the sample pad into the conjugate pad and from theconjugate pad into the membrane through capillary action. The capillaryflow rate depends on the material used (e.g., what the material is madeof, the porosity of the material, the grade of the material, etc.) tomake the sample pad, the conjugate pad, and the membrane. The timeallowed for the binding between the analyte and the labeled antibody onthe conjugate pad (conjugate time), or the time allowed for theimmunocomplex fluid to travel through the membrane pad over the testline and the control line (flow time), therefore, depends on the lengthand the type of material used for the conjugate pad and the membrane padrespectively.

Controlling the conjugate time and the flow time based on the length andthe type of material used for the conjugate pad and the membrane,however, suffers from several drawbacks. Selecting different types ofmaterial for the conjugate pad and the membrane would typically providea capillary flow rate that ranges from approximately 60 seconds percentimeter (cm) to approximately 10 seconds per cm. As the requiredconjugate time for a test increases, the length of the conjugate pad hasto increase. For example, a conjugate time of one hour may require aconjugate pad (even when the materials with the slowest flow rate areused), that is too long to be practical to use in a handheld or portablelateral flow assay due to the length of the conjugate pad, as well asthe amount of sample that may be required. In addition, the capillaryflow rate may be difficult to estimate and may vary among differentspecimens of the same type and the same brand of conjugate pad.Accordingly, a precise conjugate time or flow time may not be achievableeven when a shorter conjugate time and/or a shorter flow time isrequired.

Some of the present embodiments solve the aforementioned problems byplacing a removable physical barrier between the conjugate pad and themembrane. After the desired conjugate time is achieved, the barrier maybe removed to allow the sample fluid to flow from the conjugate pad intothe membrane. The barrier may be made of a material (e.g., plastic)which blocks the sample fluid from flowing from conjugate pad into themembrane. The barrier material is selected from material that do notreact with the sample fluid.

In some of the present embodiments, a solenoid, an electromagnet, aservo (also referred to as a servo motor or servomotor), or a linearactuator may be used to remove the barrier after a specific amount oftime from the start of the test. For example, at the start of the assaytest, a timer may be set to provide a desired conjugate time. After thetimer is expired, a signal may be generated to cause the solenoid, theelectromagnet, the servo, or the linear actuator to remove (e.g., by apulling action) the barrier from between the conjugate pad and themembrane. In some of the present embodiments, the barrier may beattached to a magnet or may include a hole, a groove, and/or a string tofacilitate the barrier removal.

In some of the present embodiments, the solenoid, the electromagnet, theservo, or the linear actuator may be a part of the lateral flow assaydevice. In other embodiments, the solenoid, the electromagnet, theservo, or the linear actuator may be a part of a separate non-disposabledevice that couples with the lateral flow assay during the testing. Insome of the present embodiments, the lateral flow assay device mayinclude a housing that may apply pressure to the conjugate pad, themembrane pad, or both. The pressure may facilitate the conjugate pad andthe membrane touching each other after the barrier is removed.

Some of the present embodiments may include a removable physical barrierto prevent the sample fluid to flow from the test line towards thecontrol line and the wicking pad. After a desired time is achieved forthe immobilized molecules at the test line to bind with the fluidmaterial, the barrier may be removed to allow the sample fluid to flowfrom the test line towards the control line and the wicking pad. Some ofthe present embodiments may include a removable physical barrier toprevent the sample fluid to flow from the control line towards thewicking pad. After a desired time is achieved for the immobilizedmolecules at the control line to bind with the fluid material, thebarrier may be removed to allow the fluid material to flow from thecontrol line towards the wicking pad. Some of the present embodimentsmay include more than of the aforementioned three barriers.

The lateral flow assay device may include a replaceable cartridge thatmay be intended for single use. The lateral flow assay device mayinclude a cartridge bed for holding the cartridge in place. The lateralflow assay device may include a backing card that is used to assembledifferent portions of the sample receiving zone. In some embodiments,each of the sample, conjugate, membrane, and wicking pads may have aseparate backing card. Depending on the type of material used for thepads and the backing card, and/or the way the pads are placed on thecartridge bed, even when a physical barrier is in place, some of fluidmaterial may leak from under the pads that are on either side of thebarrier. To prevent such a leak, some embodiments may include apermanent gap in the cartridge bed and/or in the backing card in orderto prevent the fluid material to leak from under a pad on one side of abarrier to a pad on the other side of the barrier while the barrier isin place. Once the barrier is removed, the fluid may flow freely in thedirection of the flow path.

In some embodiments, the barrier may not be pulled out of the cartridgeat once. Instead, the barrier between the conjugate pad and the membranemay be partially pulled out and then pushed back several times in orderto repeatedly bring the conjugate pad and the membrane in touch witheach other and then separate them from each other. Repeatedly connectingand disconnecting the conjugate pad and the membrane may be used tocontrol the flow of fluid material from the conjugate pad into themembrane, which in turns control the flow time over the membrane.

The number of times the barrier is pulled out and pushed back into thecartridge, the duration that the barrier stays in or out of thecartridge, and the time between the pulling and pushing actions maycontrol the amount of contact between the conjugate pad and themembrane. The amount of contact between the conjugate pad and themembrane may in turn be used to control the flow time (the time it wouldtake for the fluid material to travel the membrane length over the testline and the control line and reach the wicking pad). A similartechnique may be used to partially pull out and then push back thebarrier that prevents the flow of the fluid material from the test linetowards the control line and/or the barrier that controls the flow ofthe fluid material from the control line towards the wicking pad.

Some of the present embodiments may place a gap (instead of a physicalbarrier) between the conjugate pad and the membrane. The gap may besubstantially occupied by air and may not allow the liquid material toflow from the conjugate pad into the membrane. After the desiredconjugate time is achieved (e.g., after a timer expires), the gap may beremoved by pressing the conjugate pad and the membrane together. Afterthe gap is removed, the liquid material may flow from the conjugate padinto the membrane by capillary action.

In some of the present embodiments, the gap may be maintained by amovable section of the lateral flow assay device's housing. After adesired time is achieved, the gap may be removed by moving the movablesection of the housing towards the membrane until the conjugate pad andthe membrane come into contact with each other. In some of the presentembodiments, a solenoid, an electromagnet, a servo, or a linear actuatormay be used to move the movable section of the housing to remove the gapafter a specific amount from the start of the test. For example, at thestart of the assay test, a timer may be set to provide a desiredconjugate time. After the timer is expired, a signal may be generated tocause the solenoid, the electromagnet, the servo, or the linear actuatorto push the movable section of the housing to remove the gap. In some ofthe present embodiments, the solenoid, the electromagnet, the servo, orthe linear actuator may be a part of the lateral flow assay device. Inother embodiments, the solenoid, the electromagnet, the servo, or thelinear actuator may be a part of a separate non-disposable device thatcouples with the lateral flow assay during the testing.

In some of the present embodiments, the gap may be maintained by one ormore small poles (pillar, rods) and/or springs between the conjugate padand the membrane. In some of the present embodiments, a solenoid, anelectromagnet, a servo, or a linear actuator may be used to pull (orpush) the pole(s) or the spring(s) to remove the gap after a specificamount from the start of the test. For example, at the start of theassay test, a timer may be set to provide a desired conjugate time.After the timer is expired, a signal may be generated to cause thesolenoid, the electromagnet, the servo, or the linear actuator to pull(or push) the pole(s) or the spring(s) to remove the gap. In some of thepresent embodiments, the solenoid, the electromagnet, the servo, or thelinear actuator may be a part of the lateral flow assay device. In otherembodiments, the solenoid, the electromagnet, the servo, or the linearactuator may be a part of a separate non-disposable device that coupleswith the lateral flow assay during the testing.

Some of the present embodiments may include a gap to prevent the fluidmaterial to flow from the test line towards the control line and thewicking pad. After a desired time is achieved for the immobilizedmolecules at the test line to bind with the fluid material, the gap maybe removed to allow the fluid material to flow from the test linetowards the control line and the wicking pad. Some of the presentembodiments may include a gap to prevent the fluid material to flow fromthe control line towards the wicking pad. After a desired time isachieved for the immobilized molecules at the control line to bind withthe fluid material, the gap may be removed to allow the fluid materialto flow from the control line towards the wicking pad. Some of thepresent embodiments may include more than of the aforementioned threegaps.

In some embodiments, the gap between the conjugate pad and the membranemay be repeatedly opened and closed to control the flow of fluidmaterial from the conjugate pad into the membrane. The number of timesthe gap is opened and closed, the duration that the gap remains open orclosed, and the time between the opening and the closings of the gap maycontrol the amount of contact between the conjugate pad and themembrane. The amount of contact between the conjugate pad and themembrane may in turn be used to control the flow time. A similartechnique may be used to repeatedly open and close the gap that controlthe flow of the fluid material from the test line towards the controlline and/or the gap that controls the flow of the fluid material fromthe control line towards the wicking pad.

In some embodiments, the backing card of conjugate pad or the backingcard of the membrane pad may be curved to initially (e.g., prior to thestart of a test and for a time period after the start of the test)prevent the pads from touching each other. A mechanism such as asolenoid, a small linear actuator, or a small servo motor may be used torepeatedly bring the conjugate pad and the membrane in touch with andthen separate them from each other. Repeatedly connecting anddisconnecting the conjugate pad and the membrane may be used to controlthe flow of fluid material from the conjugate pad into the membrane.

The connecting and disconnecting of the conjugate pad and the membranemay be done according to an algorithm controlled by a processor of thelateral flow assay device. The processor may use three parameters togenerate one or more signals to connect and disconnect the conjugate padand the membrane pad in order to control the flow time of the fluid fromthe time the fluid starts at the beginning of the membrane to the timethe fluid reaches the wicking pad. The three parameters are the numberof times the pads are connected (or disconnected), the duration of eachconnections, and the duration of each disconnection (or the time betweenconsecutive connection and disconnections).

The longer the duration of each connection, the more fluid istransferred from the conjugate pad to the membrane. These threeparameters may be calculated by the processor using an algorithm and aset of calibration tables or calibration curves. The algorithm input maybe the desired conjugation time and flow time.

FIG. 1 is an upper front perspective view of one example embodiment of aportion of a lateral flow assay device 100, according to various aspectsof the present disclosure. The lateral flow assay (also referred to aslateral flow immunochromatographic assay or lateral flow dipstickimmunoassay) device 100 may be a portable device (e.g., a handhelddevice or benchtop device) that is used to analyze a sample fluid (alsoreferred to as matrix) to determine the presence and/or the amount ofone or more analytes (referred to as target analytes). In thisspecification, the terms lateral flow assay device and lateral flowassay are interchangeably used to refer to a device that performslateral flow tests.

The lateral flow assay device 100 may include a replaceable cartridgethat may be intended for single use. For example, the components shownin FIG. 1 may be part of a disposable cartridge of the lateral flowassay device 100. As described below, the lateral flow assay device 100may also include components such as actuators, processors, displays,etc., that may or may not be disposable. The non-disposable componentsof the lateral flow assay device may be used for performing multipletests for the same or different subjects (e.g., the same person ordifferent persons).

The sample may be human or animal bodily fluid, such as, withoutlimitations, one or more of urine, blood, serum, plasma, saliva, sweat,milk, mucous, semen, vaginal or urethral secretions, etc. The sample mayalso be a fluid taken from sources other than a human or an animal. Forexample, the sample may contain plant material, fuel, food, drink,animal feed, drugs, chemical compounds, etc. The sample may naturally bea liquid, may be a liquid diluted with another liquid, such as water, ormay have originally been in a solid form (e.g., a tissue sample) and istreated to be in liquid form for the application to the lateral flowassay device 100. The target analytes may be substances such as, withoutlimitations, proteins, haptens, enzymes, hormones, infectious diseaseagents, immunoglobulins, polynucleotides, steroids, drugs, nucleicacids, markers for gene mutations, etc.

I. Using Removable Physical Barriers in the Flow Path to Control theFlow and Flow Time

With reference to FIG. 1, the lateral flow assay device 100 may includea sample receiving zone 101, a labeling zone 102, a barrier zone 103, acapture zone 104, and optionally a wicking zone 105. The samplereceiving zone 101, the labeling zone 102, the capture zone 104, and thewicking zone 105 may be made of materials that make a fluid sampleapplied to the sample receiving zone 101 flow by capillary actiondownstream (i.e., from the sample receiving zone 101 towards the wickingzone 105) from each zone 101, 102, and 104 into the next adjacent zone102, 104, and 105, respectively.

The sample receiving zone 101 may include a sample pad (also referred toas sample strip or sample receiving member) 150. The sample pad 150 maybe made of natural and/or synthetic porous, microporous, mesoporous, ormacroporous materials capable of receiving a sample fluid and laterallyconducting the sample fluid towards the labeling zone 102 by capillaryaction. The sample pad 150 may be made of a material such as, withoutlimitations, cellulose, nitrocellulose, paper, silica, cotton, glass(e.g., glass fiber), or synthetic material (e.g., polyester,polyethylene, polymers, rayon, nylon, etc.). Depending on the type ofthe sample (e.g., urine, saliva, blood, etc.), the sample pad 150 may betreated by a buffer (e.g., an organic compound such as tris ortris(hydroxymethyl)aminomethane) to mitigate sample variabilities (pH,protein concentration, viscosity, salt concentration, etc.). During themanufacture of the sample pad 150, the buffer compound may be coated,impregnated, or otherwise applied or deposited on the sample pad 150 andthen dried.

With further reference to FIG. 1, the labeling zone 102 may include aconjugate pad 110 that is fluidically connected (i.e., capable ofreceiving fluid, e.g., by capillary action) to the sample pad 150. Inthe depicted embodiment, the sample pad 150 is in contact with andpartially covers the conjugate pad 110. In other embodiments, the samplepad 150 may be in more contact or less contact with the conjugate pad110 in order to provide slower or faster binding reagent and/orconjugate release respectively. A sample fluid that is applied to thesample pad 150 may be laterally transferred from the sample pad 150 tothe conjugate pad 110 by capillary action.

The conjugate pad 110 may be made of natural and/or synthetic porous,microporous, mesoporous, or macroporous materials capable of receivingthe sample fluid from the sample pad 150. The conjugate pad 110 may bemade of material such as, without limitations, glass (e.g., glassfiber), cellulose, nitrocellulose, paper, silica, cotton, or syntheticmaterial (e.g., polyester, polyethylene, polymers, rayon, nylon, etc.).

The conjugate pad may contain a binding reagent (also referred to asantibody) that is capable of binding to the target analyte in the samplefluid. The binding reagent may be coupled to a label (also referred toas conjugate, detection conjugate, probe, or detector nanoparticle)which, in its natural state, is readily visible either to the naked eye,or with the aid of an optical filter. Depending on the type of thelateral flow assay, the binding reagent may be an antibody, an antigen,a protein, a nucleic acid, etc., that is capable of binding to thetarget analyte. The label may be made of small particles (e.g.,nanoparticles), such as, without limitations, metallic sols (e.g.,colloidal gold or gold sol), dye sols, colored latex particles, carbon,etc. During the manufacture of the conjugate pad 110, the labeledbinding reagent may be coated, impregnated, or otherwise applied ordeposited on the conjugate pad 110 and then dried.

After the sample fluid flows from the sample pad 150 into the conjugatepad 110, the sample fluid may solubilize the labeled binding reagent. Ifthe sample fluid contains the target analyte, the target analyte maybind with the labeled binding reagent and form an immunocomplex. Thelabeled binding reagents that do not bind with the target analyte (e.g.,when the sample fluid does not include the target analyte or there isexcess labeled binding reagent) flow downstream towards the capture zone104 by capillary action. As described below, some of the presentembodiments may include a barrier zone 103 that may initially block thesample fluid and any other material in the flow path (e.g., unboundlabeled binding reagents, wash fluid, etc.) from flowing from thelabeling zone 102 into the capture zone 104. The sample fluid and anyother material in the flow path (e.g., unbound labeled binding reagents,wash fluid, etc.) are herein referred to as fluid material.

Depending on the type of test performed by the lateral flow assaydevice, the device may not include separate sample and conjugate pads insome embodiments and may only include the conjugate pad 110. Althoughthe sample pad 150 is shown to go over the conjugate pad 110, in someembodiments, the conjugate pad 110 may go over the sample pad 150.

The capture zone 104 may include a membrane 115 and a test line (or testzone) 125 that may be embedded in the membrane. The capture zone 104 mayoptionally include a control line (or control zone) 130 that may beembedded in the membrane 115. The membrane 115 may be made of a materialsuch as, without limitations, cellulose, nitrocellulose, paper, silica,cotton, glass (e.g., glass fiber), or synthetic material (e.g.,polyester, polyethylene, polymers, rayon, nylon, etc.) that allow thefluid material to flow downstream from the conjugate pad 101 into themembrane 115 and from the membrane 115 towards the wicking zone 105 bycapillary action. Although the conjugate pad 110 is shown to go over themembrane 115, in some embodiments, the membrane 115 may go over theconjugate pad 110.

The test line 125 may be made of a porous material such as, withoutlimitations, cellulose, nitrocellulose, paper, silica, cotton, glass(e.g., glass fiber), or synthetic material (e.g., polyester,polyethylene, polymers, rayon, nylon, etc.). The test line 125, in asandwich assay format, may contain an unlabeled binding reagent that isimmobilized on the test line 125 and does not flow downstream whenporous material of the test line is moistened (e.g., by the fluidmaterial). Depending on a particular test made by the lateral flow assaydevice 100, the binding reagent immobilized on the test line may be thesame or different than the binding reagent contained on the conjugatepad 110.

In the sandwich assay format, the binding reagent contained on the testline 125 may be an immobilized antibody that is capable of biding to theimmunocomplex that is formed from the binding of the analyte with thelabelled binding reagent on the conjugate pad 110. As the immunocomplexmoves over the test line 125, the immunocomplex binds with theimmobilized antibody on the test line 125, resulting in a secondimmunocomplex that colors the test line 125. The intensity of thecolored test line is correlated with the density of the analyte in thesample fluid. The second immunocomplex includes the analyte that isbound with the labelled binding reagent at one site and is bound withthe immobilized biding agent at another site. When the sample fluid doesnot include the target analyte, no immunocomplex is formed on theconjugate pad 110 and no immunocomplex binds with the immobilizedantibody on the test line 125. As a result, the test line 125 does notchange color.

In a competitive assay format, the test line 125 may contain theimmobilized analyte molecule (or a protein-analyte complex). If thesample liquid does not contain the analyte, the labeled antibody that issolubilized by the sample liquid may flow from the conjugate pad 110into the test line 125 and may bind to the analyte at the test line 125,resulting in a colored test line 125 that indicates the lack of thetarget analyte in the sample liquid. If the target analyte is present inthe sample liquid, the analyte may bind to the labeled antibodies on theconjugate pad 110 and may prevent the labeled antibody to bind to theanalyte at the test line 125. As a result, the test line 125 may notchange color, indicating the presence of the analyte in the samplefluid.

The capture zone 104 may optionally include a control line (or controlzone) 130 that may be embedded in the membrane 115. The control line 130may be made of a porous material such as, without limitation, cellulose,nitrocellulose, paper, silica, cotton, glass (e.g., glass fiber), orsynthetic material (e.g., polyester, polyethylene, polymers, rayon,nylon, etc.). In a sandwich assay format, the control line 130 maycontain an immobilized antibody that binds to the free labeled bindingreagents resulting in a colored control line 130, which confirms thatthe test has operated correctly regardless of whether or not the targetanalyte has been present in the sample. In a competitive assay format,the control line 130 may contain an immobilized analyte molecule (or aprotein-analyte complex) that binds to the free labeled binding reagentsresulting in a colored control line 130, which confirms that the testhas operated correctly regardless of whether or not the target analytehas been present in the sample.

The fluid material that do not bind to the test line 125 or the controlline 130 may continue to flow from the capture zone 104 into the wickingzone 105. The wicking zone 105 may include a wicking pad 120 to absorbthe fluid material that are not taken up by the test line 125 and thecontrol line 130 while maintaining the capillary flow from the membrane125 into the wicking pad 120. The wicking pad 120 may be made of aporous material such as, without limitations, cellulose, nitrocellulose,paper, silica, cotton, glass (e.g., glass fiber), or synthetic material(e.g., polyester, polyethylene, polymers, rayon, nylon, etc.). Dependingon the type of test performed by the lateral flow assay device, thedevice may not include a wicking zone 105 or a wicking pad 120. Althoughthe wicking pad 120 is shown to go over the membrane 115, in someembodiments, the membrane 115 may go over the wicking pad 120.

In some of the present embodiments, the analyte in the sample fluid mayrequire more time to bind with the labeled binding reagent than the timeit takes for the sample fluid to flow by capillary action through theconjugate pad 110 into the membrane 115. For example, withoutlimitation, the target analyte may inherently require a long time tobind with the labeled binding reagent. The required binding time maydepend on the type and concentration of the target analyte and thelabeled binding reagent.

If the analyte is not provided enough time on the conjugate pad 110 tobind with the labeled binding reagent, there may not be enoughimmunocomplex in fluid that flows to the test line 125 to bind with theimmobilized binding reagent on the test line 125 in a sandwich assayformat (or with the immobilized analyte/protein-analyte complex in acompetitive assay format) to generate a strong color signal at the testline 125 to indicate the presence or absence of the target analyte inthe sample fluid. Furthermore, it may be desirable to precisely controlthe time allowed for the analyte to bind with the labeled bindingreagent regardless of the amount of time required for the analyte tobind with the labeled binding reagent on the conjugate pad.

Some of the present embodiments provide a barrier zone 103 between thelabeling zone 102 and the capture zone 104. The barrier zone 103 mayinclude a removable barrier 135. In the embodiment depicted in FIG. 1,the removable barrier is a physical barrier made of solid material(e.g., a thin film of material) that prevents the flow of the fluidmaterial from the labeling zone 102 into the capture zone 104. Thephysical barrier 135 may be made of materials that do not react with thesample fluid and any other material in the flow path (e.g., unboundlabeled binding reagents, wash fluid, etc.). In other embodiments (e.g.,as shown in FIG. 20 described below) the barrier zone 103 may include agap that may be substantially occupied by air.

In some of the present embodiments, a timer is programmed to allow timefor the analyte in the sample fluid to bind with the labeled bindingreagent on the conjugate pad 110. The timer may start at the beginningof the test (e.g., substantially at or around the same time as thesample liquid is applied to the sample pad 150). The timer may be setsuch that enough time is allowed for the sample fluid to flow from thesample pad 150 into the conjugate pad 110 and for the analyte (if any)in the sample fluid to bind with the labelled binding reagent on theconjugate pad 110.

After the timer expires, the physical barrier 135 may be removed frombetween the labeling zone 102 and the capture zone 104 in order tofluidically connect the conjugate pad 110 in the labeling zone 102 tothe membrane 115 in the capture zone 104. After the conjugate pad 110and the membrane 115 come to contact to each other, the fluid materialmay flow from the labeling zone 102 into the capture zone 104 bycapillary action.

The lateral flow assay device 100 may include a backing card 140 that isused to assemble different portions of the sample receiving zone 101,the labeling zone 102, the capture zone 104, and the wicking zone 105.The backing card, in some embodiments, may be a continuous piece thatmay go under the pads 150, 110, 115, and 120. In other embodiments, eachpad may have a separate backing card. For example, during themanufacturing of the device, a roll or sheet of backing material may beused such that the width of the roll or the sheet is the same as (or iscut to be the same as) the length of the lateral flow assay cartridge(i.e., in the pictured orientation, from the left end of the sample pad150 to the right end of the wicking pad 120). The membrane pad 115, theconjugate pad 110, the sample pad, 150, and the wicking pad 120 are thenplaced on the backing card with the proper overlaps (e.g., as shown inFIG. 1). The pads may, for example, be connected to the backing cardwith a two sided tape or a glue. The pads and the attached backing cardmay then be cut into separate strips and each strip may be used to makea different lateral flow assay device.

Alternatively, each pad may be separately connected to a correspondingbacking card. The pads with the corresponding backing cards may then beassembled over each other with the proper overlaps to make a lateralflow assay device. The lateral flow assay device 100 may include ahousing. In FIG. 1, only a portion of the housing that includes thecartridge bed 170 is shown for simplicity.

In some of the present embodiments, the lateral flow assay may include ahousing that may apply pressure to the conjugate pad 110, the membranepad 115, or both. The pressure may facilitate the conjugate pad 110 andthe membrane 115 touching each other after the barrier 135 is removed.FIG. 2 is an upper front perspective view of one example embodiment of aportion of a lateral flow assay device 100 showing a cross section ofthe lateral flow assay device's housing, according to various aspects ofthe present disclosure. With reference to FIG. 2, the perspective showsa cross sectional view of the housing 205 across the surfaces 206.

The housing 205 may include a sample port 210 for applying the sampleliquid to the sample pad 150. The housing 205 may also include anopening 215 for viewing the test line 125. The embodiments that includea control line 130, may also include an opening 220 for viewing thecontrol line 130. Some embodiments may include one opening for viewingboth the test line 125 and the control line 130. The housing 205 mayinclude a cartridge bed 170 for holding the lateral flow assay device'scartridge.

In some of the present embodiments, the housing applies pressure to theconjugate pad 110 and/or the membrane 115 such that when the barrier 135is removed, the conjugate pad 110 and the membrane 115 come to contactwith each other to allow the fluid material in the flow path to flowfrom the conjugate pad 110 into the membrane 115 by capillary act.

For example, portions 225-226 of the housing 205 may touch the conjugatepad 110 and apply a force (as shown by the arrows 250) to push theconjugate pad 110 towards the barrier 135 and the membrane 115. In someembodiments, the portions 225-226 of the housing 105 may touch a portionof the conjugate pad 110 across a line that is perpendicular to the flowpath (the flow path runs from the left to right across the lateral flowassay device 100 in FIG. 2). In other embodiments, the portions 225-226of the housing 205 may be in the form of one or more columns that touchthe conjugate pad 110 at one or more places. In addition to, or in lieuof, pushing the conjugate pad 110 towards the barrier 135 and themembrane 115, the housing 205 may apply a force (as shown by the arrows255) to push the cartridge bed 170, backing card 140, and the membrane115 towards the barrier 135 and the conjugate pad 110.

FIG. 3 is an upper front perspective view of one example embodiment of aportion of a lateral flow assay device 100 showing the removal of thebarrier 135, according to various aspects of the present disclosure. Thefigure as shown, includes two operational steps 301 and 302.

With reference to FIG. 3, step 301 shows an initial state where thebarrier 135 is between the conjugate pad 110 and the membrane 115. Thebarrier may be made of a material (e.g., plastic, latex, metal, etc.)which blocks the fluid material from flowing from conjugate pad 110 intothe membrane 115. The barrier's material is selected from materials thatdo not react with the fluid material in the flow path. As shown in step301, the barrier 135 is flexible and follows (as shown by the dashedlines 335) the contours of the membrane 115 and the conjugate pad 110.

In some of the present embodiments, the lateral flow assay device 100 atthe start of a test may include the barrier 135 between the conjugatepad 110 and the membrane 115. For example, lateral flow assay device 100may be manufactured in the configuration shown in step 301 of FIG. 3. Atest may start by applying a sample fluid to the conjugate pad 110(e.g., through the sample port 210 of FIG. 2). In some of the presentembodiments, a timer is programmed to allow time for the analyte (ifany) in the sample fluid to bind with the labeled binding reagent on theconjugate pad 110.

In step 302 of FIG. 3, the barrier 135 is removed (as shown by the arrow360) from between the conjugate pad 110 and the membrane 115. Forexample, the barrier 135 may be removed after the expiration of thetimer. The force that is applied by the housing 205 of FIG. 2 to theconjugate pad 110 (as shown by the arrows 250) and/or by the force thatis applied to the cartridge bed 170, the backing card 140, and themembrane 115 (as shown by the arrows 255) may make the conjugate pad 110and the membrane 115 to come in contact with each other and allow thefluid material to flow from the conjugate pad 110 into the membrane 115by capillary act. Since the barrier is made of a flexible and relativelythin film of material, the barrier may take a substantially uniformshape (as shown in step 302) after the barrier 135 is pulled out and isno longer under pressure from the conjugate pad 110 and/or the membrane115.

In some of the present embodiments, one or more pieces of magnet may beattached to the barrier 135 to facilitate pulling the barrier 135 outfrom between the conjugate pad 110 and the membrane 115. FIG. 4 is anupper front perspective of one example embodiment of a physical barrierwith a piece of magnet attached to it, according to various aspects ofthe present disclosure. As shown in FIG. 4, a piece of magnet (e.g., inthe shape of a thin strip of magnetic material, in an arbitrary shape,etc.) 405 is attached to one side 410 of the physical barrier 135. Thepiece of magnet 405 may facilitate pulling the barrier 135 by anothermagnet attached to a moving shaft. In some of the present embodiments,more than one piece of magnet may be attached to the side 140 of thephysical barrier 135.

FIG. 5 is a functional block diagram illustrating one example embodimentof a linear actuator 525 that may be used for pulling out the physicalbarrier of a lateral flow assay device, according to various aspects ofthe present disclosure. The linear actuator 525 may include an electricmotor 530, a rotating shaft 580, a rotational to linear movementconverter 535, and a linear moving shaft 540. The electric motor 530, insome embodiments, may be a miniaturized motor (e.g., a micro motor). Theelectric motor 530 may include a rotor 570 that may rotate and cause therotating shaft 580 to rotate.

The rotational movement of the rotating shaft 580 may be converted tolinear movement of the linear moving shaft 540 by the rotational tolinear movement converter 535. The rotational to linear movementconverter 535 may be a set of one or more screws, a wheel and axle,and/or a set of one or more cams that receive a rotational movement fromthe rotating shaft 580 and move the linear moving shaft 540 in astraight line.

The linear moving shaft 540 may move in and out in a straight linetowards or away from the rotating shaft 580. Some of the presentembodiments may include one or more magnets 545 (only one magnet isshown) at the end of the linear moving shaft 540. In some of the presentembodiments, a processor (or controller) 505 may be used to set a timerto determine the time to pull out the barrier 135. Although the termsprocessor or controller are used in several examples in thisspecification, it should be understood that these terms apply todifferent types processing units, processors, central processing units(CPUs), microprocessors, and/or microcontrollers. The processor (orcontroller) 505 may include a single-core processor or a multi-coreprocessor in different embodiments.

In some embodiments, the processor 505 may be associated with, andcommunicatively coupled to, a user interface (UI) 550 that may include akeyboard and/or a display. The display, in some embodiments, may be atouchscreen. In addition to, or in lieu of the UI 550, the processor505, in some embodiments, may communicate with one or more clientdevices 515 to send and/or receive signals.

FIG. 5 as shown, includes two operational steps 501 and 502. Step 501shows that at the beginning of a test, the electric motor 530 may beconfigured to extend the linear moving shaft 545 away from the rotatingshaft 580, and the linear actuator 525 may be placed adjacent to thecartridge 575 of the lateral flow assay device 100 such that themagnet(s) 545 on the shaft 540 may contact the magnet(s) 405 (FIG. 4) onthe barrier 135. The cartridge 575 may include the components shown inFIGS. 1 and 3. In FIG. 5, the top view of the lateral flow assay device100 is shown and the components of the lateral flow assay device 100,other than the barrier 135, are not shown for simplicity.

In some of the present embodiments, the disposable cartridge 575 of thelateral flow assay device 100 may include a near field communication(NFC) chip (or NFC tag) 590. The NFC chip 590 may identify the test andother parameters and information related to the test including theconjugation time on the conjugate pad. The lateral flow assay device 100may also include an NFC reader 595. Once the cartridge 575 is placed inthe lateral flow assay device's 100 housing (e.g., on the cartridge bed170 of FIGS. 1-3), the NFC reader 595 (which may be located, forexample, and without limitations, under the cartridge bed 170 close towhere the NFC chip is located) may automatically detect the presence ofthe NFC tag.

The NFC reader 595 may read the information regarding the test to beperformed by the cartridge. The NFC reader 595 may be communicativelycoupled with the processor 505. The processor 505 may receive theinformation from the NFC reader and, for example, and withoutlimitation, may start a timer to control the conjugate times, may send asignal to activate the electric motor to remove the barrier 135, maydisplay some of the information on its display of the UI 550, and/or maysend some of the information and parameters to one or more externaldevices such as the client device 515.

In some embodiments, all components of the lateral flow assay device,including the processor 505, the UI 550, etc., may be used for one testand may be disposable. In these embodiments, in addition to, or in lieuof the NFC, the parameters and information regarding the test may bepre-programmed into the processor. In other embodiments, theprocessor/controller 505, the UI 550, the linear actuator 525, and/orthe NFC reader may be reusable for performing multiple tests for thesame or different subjects (e.g., the same person or different persons).

In some embodiments, in addition to, or in lieu of, using theinformation from the NFC tag 590, the processor 505 may receive a valuefor setting the timer through a wireless link 570 from one or moreclient devices 515 (only one client device is shown for simplicity). Theclient device 515 may be, without limitations, a cellular telephone(e.g., a smartphone), a computing device (e.g., a tablet computer, alaptop computer, a desktop computer), a personal digital assistant (PDA)device, an electronic device capable of communicating the timer value tothe processor 505, etc.

In some of the present embodiments, the processor 505 and the clientdevice 515 may each include one or more antennas 510 and may establishthe wireless link 570 through the antennas 510. Alternatively, theclient device 515 and the processor 505 may be connected by a wiredconnection (e.g., without limitation, using a cable, using a connectionsuch as USB, thunderbolt, lightning, etc.). The client device 515 mayexecute an application program that is used to interact with theprocessor 505 and/or with the lateral flow assay device 100. Forexample, the client device 515 may receive a value (e.g., from a userentering the value through a user interface of the application program)for setting a timer value in seconds, in milliseconds, in microseconds,or with any other time units. The client device 515 may then send thetimer value to the processor 505 through the wired or wirelessconnection.

In some embodiments, the processor 505 may start the timer after theprocessor 505 receives a signal indicating the start of a test. In someof the present embodiments, the signal may be received by the processor505 from the client device 515. For example, the processor 505 may startthe timer as soon as (or a period of time after) the processor 505receives the value of the timer from the client device 515. In someembodiments, the signal may be received after a physical switch (e.g., apush button or a toggle switch on the UI 550) that is communicativelycoupled to the processor 505 is activated to generate the signal.

After the time required for the analyte in the sample fluid to bind withthe labeled binding agents on the conjugate pad 110 elapses, theelectric motor 530 may receive a signal to pull the linear moving shaft545 back towards the rotating shaft 580 and away from the cartridge 575of the lateral flow assay device 100. After the timer expires, theprocessor 505 may send one or more signals to the linear actuator 525 tomove the linear moving shaft 540 to pull the barrier 135 from betweenthe conjugate pad 110 (FIG. 3) and the membrane 115 (FIG. 3) of thelateral flow assay device 100.

In step 502, as the linear moving shaft 540 is pulled away from thelateral flow assay device 100 (as shown by the arrow 541, the magnet(s)545 on the linear moving shaft 540 may pull the magnet(s) 405 (whichis/are firmly attached to the barrier 135), causing the barrier 135 topull out from between the conjugate pad 110 (FIG. 3) and the membrane115. The magnets 545 and 405 may have enough magnetic force to allowthem to connect to each other (e.g., by magnetic force) and to continueconnecting to each other while the barrier 135 is being pulled out frombetween the conjugate pad 103 and the membrane 115.

In some of the present embodiments, the magnet(s) 545 on the shaft 540is made to contact the magnet(s) 405 on the barrier at the beginning ofa test (when the barrier is located between the conjugate pad 110 andthe membrane 115 as shown in step 301 of FIG. 3). The one or moresignals may cause the electric motor 530 to generate a predeterminedamount of rotational movement to the rotating shaft 580, which is inturn is converted by the rotational to linear movement converter 535into a predetermined amount of linear movement on the linear movingshaft 540.

For example, the linear moving shaft 540 may move in a linear directionaway from the lateral flow assay device 100, causing the magnet(s) 545attached to the magnet 405(s) on the barrier 135 to pull the barrier 135from between the conjugate pad 110 (FIG. 3) and the membrane 115 (FIG.3). In some embodiments, the linear moving shaft 540 may move (in thedirection of the arrow 541) a distance that is the same as or slightlylarger than the width 415 (FIG. 4) of the barrier 135 to completely pullthe barrier 135 out of the lateral flow assay device 100.

Some of the present embodiments may use a solenoid instead of a linearactuator to pull the barrier 135. FIG. 6 is a functional block diagramillustrating one example embodiment of a solenoid 605 that may be usedfor pulling out the physical barrier of a lateral flow assay device,according to various aspects of the present disclosure.

A solenoid may function as a transducer that converts energy into linearmotion. The solenoid 605 may include an electromagnetically inductivecoil 660 that is wrapped around a movable metallic core (or armature)610. When an electric current passes through the wire 650, a magneticfield is generated by the coil 660 that causes the moveable core 610 tomove in a linear line. By changing the direction of the current, themagnetic field is reversed that causes the moveable core 610 to move inthe opposite direction. One or more magnets 615 may be attached to oneend of the moveable core 610.

The figure as shown, includes two operational steps 601 and 602. Asshown in step 601, at the beginning of a test, the solenoid 605 may beconfigured (e.g., by changing the direction of electric current in thewire 650) to extend the movable core 610 away from the solenoid 605, andthe solenoid 605 may be placed adjacent to the lateral flow assay device100 such that the magnet(s) 615 on the movable core 610 contacts themagnet(s) 405 (FIG. 4) on the barrier 135. In FIG. 6, the top view ofthe lateral flow assay device 100 is shown and the components of thelateral flow assay device 100, other than the barrier 135, are not shownfor simplicity.

The processor 505, the NFC tag 590, the NFC reader 595, and the clientdevice 515 of FIG. 6 may be similar to the corresponding components ofFIG. 5. With reference to FIG. 6, the processor 505 may receive a valuefor setting the timer from the NFC tag 590/NFC reader 595 or from theclient device 515. In some embodiments, the processor 505 may start thetimer after the processor 505 receives a signal indicating the start ofa test. In some of the present embodiments, the signal may be receivedby the processor 505 from the client device 515. For example, theprocessor 505 may start the timer as soon as (or a period of time after)the processor 505 receives the value of the timer from the client device515. In some embodiments, the signal may be received after a physicalswitch (e.g., a push button or a toggle switch on the UI 550) that iscommunicatively coupled to the processor 505 is activated to generatethe signal.

In some embodiments, all components of the lateral flow assay device,including the processor 505, the UI 550, etc., may be used for one testand may be disposable. In these embodiments, in addition to, or in lieuof the NFC, the parameters and information regarding the test may bepre-programmed into the processor. In other embodiments, theprocessor/controller 505, the UI 550, the solenoid 605, the power source640, the controller circuit 630, and/or the NFC reader may be reusablefor performing multiple tests for the same or different subjects (e.g.,the same person or different persons).

In step 602, after the timer expires, the processor 505 may send one ormore signals to the controller circuit 630 to change the direction ofcurrent in the wire 650 (e.g., by changing the polarity of the voltagethat is applied to the wire 650 by the power source 640). Changing thedirection of current in the wire 650 may change the magnetic fieldgenerated by the coil 660 that causes the moveable core 610 to movetowards the solenoid 605 and away from the lateral flow assay device100, causing the magnet(s) 615 that is attracting the magnet(s) 405(FIG. 4) on the barrier 135 to pull the barrier 135 from between theconjugate pad 110 (FIG. 3) and the membrane 115 (FIG. 3). The magnets615 and 405 may have the polarities (e.g., opposite polarities toattract each other) and enough magnetic force to allow them to connectto each other (e.g., by magnetic force) and to continue connecting toeach other while the barrier 135 is being pulled out from between theconjugate pad 103 and the membrane 115. In some embodiments, the movablecore 610 may move (in the direction of the arrow 690) a distance that isthe same as or slightly larger than the width 415 (FIG. 4) of thebarrier 135 to completely pull the barrier 135 out of the lateral flowassay device 100.

Some of the present embodiments may use an electromagnet instead of alinear actuator or a solenoid to pull the barrier 135. FIG. 7 is afunctional block diagram illustrating one example embodiment of anelectromagnet 770 that may be used for pulling out the physical barrierof a lateral flow assay device, according to various aspects of thepresent disclosure. In FIG. 7, the top view of the lateral flow assaydevice 100 is shown and the details of the lateral flow assay device100, other than the barrier 135, are not shown for simplicity.

In an electromagnet, a magnetic field is generated by an electriccurrent. The magnetic field disappears when the electric current isturned off. The electromagnet 770 may include an electromagneticallyinductive coil 705 that is wrapped around a metallic core 710. When theelectric current is turned off, the coil 705 no longer generates amagnetic field.

The figure as shown, includes two operational steps 701 and 702. Asshown in step 701, at the beginning of a test, the switch 750 may be offsuch that no current is passed through the power source 740, the wire750, and the core 710. The coil 705 may not generate a magnetic fieldand the metallic core 710 may not act as a magnet. In step 701, theelectromagnet 770 may be placed adjacent to the cartridge 575 of thelateral flow assay device 100 such that the magnet(s) 405 (FIG. 4) onthe barrier 135 is/are at a predetermined distance “d1” from the core710. The distance “d1” may be just enough to allow the removable barrier135 to be completely pulled out of lateral flow assay device 100 whenthe electromagnet 770 is turned on.

The processor 505, the NFC tag 590, the NFC reader 595, and the clientdevice 515 of FIG. 7 are similar to the corresponding components of FIG.5. With reference to FIG. 7, the processor 505 may receive the values ofthe test parameters from the NFC tag 590/NFC reader 595 or from theclient device 515. In some embodiments, the processor 505 may start thetimer after the processor 505 receives a signal indicating the start ofa test. In some of the present embodiments, the signal may be receivedby the processor 505 from the client device 515. For example, theprocessor 505 may start the timer as soon as (or a period of time after)the processor 505 receives the value of the timer from the client device515. In some embodiments, the signal may be received after a physicalswitch (e.g., a push button or a toggle switch on the UI 550) that iscommunicatively coupled to the processor 505 is activated to generatethe signal.

In some embodiments, all components of the lateral flow assay device,including the processor 505, the UI 550, etc., may be used for one testand may be disposable. In these embodiments, in addition to, or in lieuof the NFC, the parameters and information regarding the test may bepre-programmed into the processor. In other embodiments, theprocessor/controller 505, the UI 550, the coil 705, the power source740, the controller circuit 730, and/or the NFC reader may be reusablefor performing multiple tests for the same or different subjects (e.g.,the same person or different persons).

In step 702, after the timer expires, the processor 505 may send one ormore signals to the controller circuit 730 to close the switch 750 tohave a current flow from the power source 740 through the wire 750 andthe coil 705. The current in the coil 705 may cause the coil 705 togenerate a magnetic field and make the core 710 to become a magnet. Thecore 710 acting as a magnet may then magnetically attract the magnets(s)405 (FIG. 4) on the barrier 135 to pull the barrier 135 from between theconjugate pad 110 (FIG. 3) and the membrane 115 (FIG. 3). The magnetgenerated by the core 710 may have the polarity (e.g., the oppositepolarity of the magnet(s) 405) and enough magnetic force to pull themagnet(s) 405 on the barrier 135 and the barrier 135 from between theconjugate pad 103 (FIG. 3) and the membrane 115 (FIG. 3).

As shown in steps 701 and 702 of FIG. 7, the distance “d1” between thecore 710 and the cartridge 575 of the lateral flow assay device 100 maynot change as the barrier 135 is being pulled out. The distance “d1” insome embodiments is adjusted at the beginning of a test such that whenthe electromagnet is turn on (e.g., as described with reference to step702), the barrier 135 is completely pulled out of the lateral flow assaydevice 100. For example, in some embodiments, the distance “d1” may bethe same as, or slightly larger, than the width 415 (FIG. 4) of thebarrier 135.

Some of the present embodiments may use a hook instead of a magnet topull the barrier 135 from between the conjugate pad 110 and the membrane115. FIG. 8 is an upper front perspective of one example embodiment of aphysical barrier that includes a hole, according to various aspects ofthe present disclosure. The physical barrier 835 may be made of similarmaterials as the physical barrier 135 (FIGS. 1-4).

With reference to FIG. 8, the physical barrier 835 may have a width 815that is wider than the width of the conjugate pad 110 and the membrane115. The barrier 835 may be initially (e.g., at the manufacture time ofthe lateral flow assay device and/or at the beginning of a test) placedbetween the conjugate pad 110 and the membrane 115 in such a way thatthe barrier 835 prevents the flow of the fluid material from theconjugate pad 110 into the membrane 115 and a portion 810 of the barriercomes out of the lateral flow assay device housing 205 of FIG. 2.

As shown in FIG. 8, the portion 810 of the physical barrier 835 thatcomes out of the lateral flow assay device housing may include one ormore holes 805 (only one hole is shown in FIG. 8). The hole 805 may beused to pass a hook through the hole 805 to pull the barrier 835 frombetween the conjugate pad 110 and the membrane 115 (FIG. 3).

FIG. 9 is a functional block diagram illustrating one example embodimentof the linear moving shaft of FIG. 5 with a hook that is used forpulling out the physical barrier of a lateral flow assay device,according to various aspects of the present disclosure. The linearmoving shaft 910 in FIG. 9 is similar to the linear moving shaft 540 ofFIG. 5 except that the linear moving shaft 910 has a hook 905, insteadof a magnet, attached to one end of the linear moving shaft 910.

The linear moving shaft 910 may be part of a linear actuator similar tothe linear actuator of FIG. 5. The hook 905 may fit into the hole 805 ofFIG. 8. In the embodiments that the barrier 835 includes more than onehole 805, the linear moving shaft may include the same number of hooks905 as the holes 805. When the linear moving shaft 910 is moved awayfrom the lateral flow assay device (e.g., after the timer describedabove is expired), the hook pulls out the physical barrier 837 frombetween the conjugate pad 110 and the membrane 115. When the physicalbarrier 835 has more than one hole 805, the hook 905 may have more thanone head to fit in the holes 805.

A hook similar to the hook 905 may be placed on the movable core 610 ofFIG. 6 (instead of a magnet 615) in order to pull out the physicalbarrier 835 from between the conjugate pad 110 and the membrane 115. Insome of the present embodiments, a string may pass through the hole(s)805 of FIG. 5 and the string may be used to pull the physical barrier835 from between the conjugate pad 110 and the membrane 115 (e.g., byusing a linear actuator or a solenoid as described above).

In some of the present embodiments, the physical barrier may be manuallypulled out from between the conjugate pad 110 and the membrane 115. Forexample, the string described above may be used to manually pull thebarrier out (e.g., after the timer described above expires and theprocessor 505 of FIGS. 5-6 makes a visual and/or audible signal toindicate that the timer has expired). FIG. 10 is an upper frontperspective of one example embodiment of a physical barrier thatincludes a groove for pulling out the physical barrier of a lateral flowassay device, according to various aspects of the present disclosure.The physical barrier 1035 may be made of similar materials as thephysical barrier 135 (FIGS. 1-4).

With reference to FIG. 10, the physical barrier 1035 may a have a width1015 that is wider than the width of the conjugate pad 110 (FIG. 1) andthe membrane 115 (FIG. 1). The barrier 1035 may be initially (e.g., atthe manufacture time of the lateral flow assay device and/or at thebeginning of a test) placed between the conjugate pad 110 and themembrane 115 in such a way that the barrier 1035 prevents the flow ofthe sample fluid from the conjugate pad 110 into the membrane 115 and aportion 1010 of the barrier comes out of the lateral flow assay devicehousing 205 of FIG. 2.

The physical barrier 1035 may a have a groove 1005 in the portion 1010of the physical barrier 1035 that comes out of the lateral flow assaydevice's housing 205. The groove 1005 may be used to manually pull outthe barrier 1035 from between the conjugate pad 110 and the membrane 115(e.g., after the timer described above expires and the processor 505 ofFIG. 5 or 6 makes a visual and/or audible signal to indicate that thetimer has expired).

FIG. 11 is a flowchart illustrating an example process 1100 for pullingout a barrier that separates the labeling and capture zones of a lateralflow assay device, according to various aspects of the presentdisclosure. In some of the present embodiments, the process 1100 may beperformed by a processor 505 (FIGS. 5-7).

With reference to FIG. 11, the process 1100 may send (at block 1105) oneor more signals to a device to adjust the position of the device withrespect to the lateral flow assay device 100 (FIGS. 1-3 and 5-7) and/orto set up the device to pull the barrier 135 out of the lateral flowassay device. As a first example, the processor 505 of FIG. 5 may sendone or more signals to the electric motor 530 to rotate the rotatingshaft 580 to cause the linear moving shaft 540 to move such that themagnet(s) 545 on the linear moving shaft 540 come(s) in contact with themagnet(s) 405 (FIG. 4) on the barrier 135. Alternatively, the one ormore signals may cause one or more hooks 908 (FIG. 9) on the rotatingshaft 580 to engage with one or more holes 805 (FIG. 8) on the barrier135.

As a second example, the processor 505 of FIG. 6 may send one or moresignals to the controller circuit 630 to adjust the electric current inthe wire 650 and the coil 660 such that the magnet(s) 615 on the movablecore 610 come(s) in contact with the magnet(s) 405 (FIG. 4) on thebarrier 135. Alternatively, the one or more signals may cause one ormore hooks 908 (FIG. 9) on the movable core 610 to engage with one ormore holes 805 (FIG. 8) on the barrier 135. As a third example, theprocessor 505 of FIG. 7 may send one or more signals to the controllercircuit 730 to turn off the switch 750 in order for the core 710 not toact as a magnet while the core 710 is kept at a distance “d1” from thebarrier 135 as described above by reference to FIG. 7.

With further reference to FIG. 11, the process 1100 may receive (atblock 1110) a signal that may include a value to set a timer forremoving the barrier. The signal, in some embodiments, may include avalue that indicates the amount of time in a predetermined unit of time(e.g., hours, minutes, seconds, milliseconds, microseconds, etc.). Thesignal, in some embodiments, may include a value and a unit of time(e.g., 2 seconds, 45 milliseconds, etc.).

In some of the present embodiments, the process 1100 may receive, at theprocessor 505 (FIGS. 5-7), a signal that includes the test parametersvalues (e.g., and without limitations, the timer value) from the NFC tag590 and the NFC reader 595. In some of the present embodiments, theprocess 1100 may receive, at the processor 505 (FIGS. 5-7), a signalthat includes test parameters values from the client device 515. In someembodiments, the processor 505 may be associated with, andcommunicatively coupled to, a user interface including a keyboard and/ora display (e.g., a touchscreen). In these embodiments, the process 1100may receive, at the processor 505, the signal that includes the testparameter values from the keyboard and/or the touchscreen associatedwith the processor.

With continued reference to FIG. 11, the process 1100 may then set (atblock 1115) a timer to expire after a time period that is identified bythe received timer value. For example, the processor 505 may set aninternal timer to expire after a time period determined by the receivedtimer value. The process 1100 may then determine (at block 1120) whetherto start the timer.

In some of the present embodiments, the process 1100 may receive asignal to start the timer, which is different that the signal thatincludes the timer value. For example, the client device 515 (FIGS. 5-7)may receive a signal through the application executing on the clientdevice 515 indicating the start of the test. The process 1100 may thenreceive a signal, at the processor 505, from the client device 515indicating the start of the test. Alternatively, the process 1100 mayreceive the signal after a physical switch (e.g., a push button or atoggle switch) that is communicatively coupled to the processor 505 isactivated to generate the signal. In some of the present embodiments,the process 1100 may start the timer as soon as the timer value is set(at block 1115). These embodiments may bypass block 1120

When the process 1100 determines (at block 1120) that the timer shouldnot be started, the process 1100 may proceed back to block 1120.Otherwise, the process 1100 may start (at block 1125) the timer. Theprocess 1100 may then determine (at block 1130) whether the timer hasexpired. When the process 1100 determines (at block 1130) that the timerhas not expired, the process 1100 may proceed back to block 1130 to waitfor the timer to expire.

Otherwise, the process 1100 may send (at 1135) one or more signals tomove a shaft to pull the barrier from between the labeling and capturezones of the lateral flow assay device. The process 1100 may then end.As a first example, with reference to FIG. 5, the processor 505 may sendone or more signals to the electric motor 530 to rotate and cause therotational to linear movement converter 535 to move the shaft 540 apredetermined distance in order to pull the barrier 135 (FIGS. 1-4) frombetween the conjugate pad 110 and the membrane 115.

In some embodiments, the magnet(s) 545 on the linear moving shaft 540is/are made to contact the magnet(s) 405 (or the hook(s) 905 of FIG. 9is/are made to engage the hole(s) 805 of FIG. 8) on the barrier at thebeginning of a test (when the barrier is located between the conjugatepad 110 and the membrane 115). The one or more signals (sent at block1135) may be sent from the processor 505 to the electric motor 530,causing the electric motor 530 to rotate the rotating shaft 580 by apredetermined amount, the rotational to linear movement converter 535 tocause the linear moving shaft 540 to move in a linear direction (e.g.,away from the lateral flow assay device), causing the magnet(s) 545 thatis/are attached to the magnet(s) 405 (or the hook(s) 905 that is/areengaged in the hole(s) 805) on the barrier 135 to pull the barrier 1135out from between the conjugate pad 110 and the membrane 115.

As a second example, with reference to FIG. 6, the processor 505 maysend one or more signals to the controller circuit 630 to change thedirection of the electrical current in the wire 650 and cause themovable core 610 to move a predetermined distance causing the magnet(s)615 that is/are attached to the magnet(s) 405 (or the hook(s) 905 thatis/are engaged in the hole(s) 805) on the barrier 135 to pull thebarrier 1135 out from between the conjugate pad 110 and the membrane115. As a third example, the processor 505 of FIG. 7 may send one ormore signals to the controller circuit 730 to turn one the switch 750 inorder for the core 710 to act as a magnet and pull the magnet 405 (FIG.4) that is attached to the barrier 135 out of the lateral flow assaydevice 100.

With reference to FIGS. 1 and 3, the removable barrier 135 may be usedto prevent the flow of the fluid material from the conjugate pad 110into the membrane 115 until a timer expires and the barrier 135 isremoved. However, depending on the type of material used for theconjugate pad 110, the membrane pad 115, and the backing card 140,and/or the way the pads 110 and 115 are placed on the cartridge bed 170,even when the barrier 135 is in place, some of the fluid material mayleak from under the conjugate pad 110 (e.g., through the backing card140 and/or the cartridge bed 170) into the membrane 115.

To prevent such a leak, some embodiments may include a permanent gap inthe cartridge bed and/or in the backing card 140 in order to prevent thefluid material to leak from under the conjugate pad 110 into themembrane 115 while the barrier 135 is in place. Once the barrier isremoved, the fluid may flow freely from the conjugate pad 110 into themembrane 115.

FIG. 12 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device that includes a permanent gapin the backing card and/or the cartridge bed to prevent the leaking ofthe fluid material from under the conjugate pad into the membrane whilethe barrier is in place, according to various aspects of the presentdisclosure.

With reference to FIG. 12, the cartridge bed 171 and 172 may have apermanent gap 1205 such that there is no cartridge bed under a portionof the conjugate pad 110 and the membrane 115 where the barrier 135 islocated between the conjugate pad 110 and the membrane 115. In someembodiments, the cartridge bed may be made of two separate sections 171and 172, one section on each side of the cartridge bed gap 1205. The twosections 171 and 172 of the cartridge bed may be secured on the housing(as shown below with reference to FIGS. 14 and 15) of the lateral flowassay device 100.

In addition, there may be a gap 1210 in the backing card 140. In theembodiments that the conjugate pad 110 and the membrane 115 haveindividual backing cards, each backing card is made such that thebacking card of the conjugate pad and the backing card of the membranedo not touch each other.

In the depicted embodiment, a portion of the backing card that is underthe membrane has crossed over the cartridge bed gap 1205. However, thereis still a gap 1210 between the backing card that is under the membrane115 and the backing card that is under the conjugate pad 110. In otherembodiments, the backing card that is under the membrane 115 may notcross over the cartridge bed gap 1205. In yet other embodiments, theportion of the backing card that is under the conjugate pad 110 maycross over the cartridge bed gap 1205 while maintaining the gap 1210with the portion of the backing card that is under the membrane 115.

FIG. 13 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device with a permanent gap in thebacking card and/or the cartridge bed, showing the removal of thebarrier, according to various aspects of the present disclosure. Thefigure as shown, includes two operational steps 1301 and 1302.

With reference to FIG. 13, step 1301 shows an initial state where thebarrier 135 is between the conjugate pad 110 and the membrane 115. Thebarrier may be similar to the barrier 135 of FIG. 3. The cartridge bedgap 1205 and/or the backing card gap 1210 prevent the fluid material toleak from underneath the conjugate pad 100 into the membrane 115. Asshown by the arrows 1305, as long as the barrier 135 is between theconjugate pad 110 and the membrane 115, fluid material cannot flow fromthe conjugate pad 110 into the membrane 115. The cartridge bed gap 1205and/or the backing card gap 1210 provide the technical advantage ofpreventing the fluid material from leaking from under the conjugate pad110 into the membrane 115 while the barrier 135 is between the conjugatepad 110 and the membrane 115.

In step 1302 of FIG. 13, the barrier 135 is removed (as shown by thearrow 360) from between the conjugate pad 110 and the membrane 115(e.g., when a timer expires and the barrier is removed as describedabove with reference to FIGS. 5-7). As shown by the arrows 1310, oncethe barrier 135 is removed, the fluid material may flow from theconjugate pad 110 into the membrane 115.

FIG. 14 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device 100 showing a cartridge insidethe device's housing, according to various aspects of the presentdisclosure. FIG. 15 is a front elevation view of the lateral flow assaydevice of FIG. 14, according to various aspects of the presentdisclosure.

With reference to FIGS. 14 and 15, the housing 1405 may include a sampleport 1460 for applying the sample liquid to the lateral flow assaydevice 100. In the example of FIG. 14, the lateral flow assay device 100does not include a separate sample pad. As shown, the lateral flow assaydevice 100 may include a conjugate pad 110, a removable barrier 135, amembrane 115, a test line 125, a control line 130, and a wicking pad120. The conjugate pad 110 may act as both the sample pad to receive asample fluid and as the conjugate pad to contain a binding reagent thatis capable of binding to the target analyte in the sample fluid.

The lateral flow assay device 100 may include an optional plasma filter1420. When the sample fluid includes blood, the plasma filter 1420 maybe used to filter and pass the plasma while stopping the flow of redblood cells onto the conjugate pad 110.

The housing 205 may also include an opening 215 for viewing the testline 125. The embodiments that include a control line 130, may alsoinclude an opening 220 for viewing the control line 130. Someembodiments may include one opening for viewing both the test line 125and the control line 130. The housing 205 may include a cartridge bed171 and 172 for holding the lateral flow assay device's cartridge.

With further reference to FIGS. 14 and 15, the cartridge bed 171 and 172may include a permanent cartridge bed gap 1205. As shown, the barrier135 and a portion of the conjugate pad 110 and the membrane 115 arelocated over the cartridge bed gap 1205 to prevent the fluid material toleak from under the conjugate pad into the membrane 115. The twosections 171 and 172 of the cartridge bed on either side of thecartridge bed gap 1205 may be fixed to the housing 1405, for example,and without limitations, by one or more support columns/supportstructures 1430. The housing may include one or more other supportcolumns/support structures 1435 to hold the cartridge of the lateralflow assay device (that includes the components shown in FIGS. 14 and15). For simplicity, FIGS. 14 and 15 do not show the backing card 140 orthe backing card gap 1210 of FIGS. 12 and 13.

In addition to, or in lieu of, a barrier zone between the labelling zoneand the capture zone, some of the present embodiments may have one morebarrier zones at other locations to provide additional time for thesample fluid and other material in the fluid flow to bind with theimmobilized molecules at the test line and/or at the control line. Insome of these embodiments, the membrane may be made of several separatepieces (as oppose to one continuous piece of material).

FIG. 16 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device 1600 with multiple barrierzones, according to various aspects of the present disclosure. Thelateral flow assay device 1600 may include a housing, which is not shownin FIG. 16 for simplicity. Similar to the lateral flow assay device 100of FIG. 1, the lateral flow assay device 1600 may include a sample pad150 in the capture zone, a conjugate pad 110 in the labeling zone, and awicking pad 120 in the wicking zone. The capture zone of the lateralflow assay device 1600 may include two separate membranes 1615 and 1616.A test line (or test zone) 125 may be embedded in the membrane 1615. Acontrol line (or control zone) 130 may be embedded in the membrane 1616.The sample pad 150, the conjugate pad 110, the membranes 1615-1616, thetest line 125, the control line 130, and the wicking pad 120 of FIG. 16may be made of similar material as described above for the correspondingcomponents of FIG. 1.

With reference to FIG. 16, the removable physical barrier 135 betweenthe conjugate pad 110 and the membrane 1615 is substantially similar tothe removable physical barrier 135 of FIG. 1. The lateral flow assaydevice 1600 may include a barrier 1630 that may prevent fluid flow fromthe membrane 1615 and the test line 125 into the membrane 1616. Thelateral flow assay device 1600 may include a barrier 1635 that mayprevent fluid flow from the membrane 1616 and the control line 130 intothe wicking pad 120.

In some of the present embodiments, the lateral flow assay device 1600may include a housing that may apply pressure to different components ofthe lateral flow assay device 1600 in order for these components to comeinto contact with each other after the barrier between them is removed.FIG. 17 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device 1600 showing a cross section ofthe lateral flow assay device's housing, according to various aspects ofthe present disclosure. With reference to FIG. 17, the perspective showsa cross sectional view of the housing 1705 across the surfaces 1706.

Similar to the housing 205 of FIG. 2, the housing 1705 of FIG. 17 mayinclude a sample port 1710 for applying the sample liquid to the samplepad 150, an opening 1715 for viewing the test line 125, and (for theembodiments that include a control line) an opening 1720 for viewing thecontrol line 130. Some embodiments may include one opening for viewingboth the test line 125 and the control line 130.

Similar to the housing 205 of FIG. 2, the housing 1705 may applypressure to the conjugate pad 110 (e.g., as shown by the arrows 250)and/or to the membrane 115 (e.g., as shown by the arrows 255) such thatwhen the barrier 135 is removed, the conjugate pad 110 and the membrane115 come to contact with each other to allow the fluid material in theflow path to flow from the conjugate pad 110 into the membrane 115 bycapillary act.

With continued reference to FIG. 17, the housing 1700 may apply pressureto the membrane 1616 (e.g., as shown by the arrows 1750) and/or to thebacking card 140 and the membrane 1615 (e.g., as shown by the arrows1755) such that when the barrier 1630 is removed, the membrane 1616 andthe membrane 2085 come to contact with each other to allow the fluidmaterial in the flow path to flow from the membrane 1615 and the testline 125 (which is embedded in the membrane 1615) into the membrane 1616by capillary act. The housing 1600 may apply pressure to the wicking pad120 (e.g., as shown by the arrows 1760) and/or to the backing card 140and the membrane 1616 (e.g., as shown by the arrows 1765) such that whenthe barrier 1635 is removed, the wicking pad 120 and the membrane 1616come to contact with each other to allow the fluid material in the flowpath to flow from the membrane 1616 and the control line 130 (which isembedded in the membrane 1616) into the wicking pad 120 by capillaryact. With further reference to FIG. 17, the barriers 135, 1630, and 1635may be removed using any of the mechanisms described above withreference to FIGS. 3-10 for removing the barrier 135 of FIG. 3.

FIG. 18 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device showing the removal of multiplebarriers, according to various aspects of the present disclosure. Thefigure as shown, includes two operational steps 1801 and 1802. Withreference to FIG. 18, step 1801 shows an initial state where the barrier135 is between the conjugate pad 110 and the membrane 115, the barrier1630 is between the membrane 1616 and the membrane 1615, and the barrier1635 is between the wicking pad 120 and the membrane 1616. The barriers135, 1630, and 1635 may be made of materials (e.g., plastic, latex,metal, etc.) which block the fluid material from flowing downstream onthe flow path. The barriers' materials are selected from materials thatdo not react with the fluid material in the flow path. As shown in step1801, the barriers 135, 1630, and 1635 are flexible and follow (as shownby the corresponding dashed lines 335, 1631, and 1636) the contours ofthe components that the barriers 135, 1630, and 1635 are separating.

In some of the present embodiments, the lateral flow assay device 1800at the start of a test may include the barriers 135, 1630, and 1635. Forexample, the lateral flow assay device 1800 may be manufactured in theconfiguration shown in step 1801 of FIG. 18. A test may start byapplying a sample fluid to the conjugate pad 110 (e.g., through thesample port 1710 of FIG. 17).

With reference to step 1802 of FIG. 18, some of the present embodimentsmay use several timers for removing the barriers 135, 1630, and 1635.For example, a first timer may be set to allow the analyte (if any) inthe sample fluid to bind with the labeled binding agents on theconjugate pad 110. After the expiration of the first timer, the barrier135 may be removed (as shown by the arrow 360 of FIG. 18) from betweenthe conjugate pad 110 and the membrane 1615 to allow the fluid materialto flow from the conjugate pad 110 into the membrane 1615 by capillaryaction.

With continued reference to FIG. 18, after the expiration of the firsttimer, a second timer may be started to determine the time for removingthe barrier 1630. In some of the present embodiments, the labelledimmunocomplex in a sandwich format assay may require more time to bindwith the immobilized binding reagent at the test line than the time ittakes for the fluid material to flow by capillary action through thetest line 125 into the membrane 1616. The second timer may allow enoughtime for the binding of the labelled immunocomplex with the immobilizedbinding reagent at the test line.

Similarly, in a competitive assay format, the labelled binding reagentin the fluid may require more time to bind with the immobilizedanalyte/protein-analyte complex in the test line. The second timer mayallow enough time for the binding of the labelled binding reagent withthe immobilized binding reagent at the test line. After the expirationof the second timer, the barrier 1630 may be removed (as shown by thearrow 1831) from between (i) the membrane 1615, the test line 125 and(ii) the membrane 1635 to allow the fluid material to flow from themembrane 1615 and the test line 125 into the membrane 1616 by capillaryaction.

After the expiration of the second timer, a third timer may be startedto determine the time for removing the barrier 1635. In some of thepresent embodiments, the free labeled binding reagents may require moretime to bind with the immobilized antibody in a sandwich format assay atthe control line than the time it takes for the fluid material to flowby capillary action through the control line 130 into the wicking pad120. Similarly, in a competitive assay format, the free labeled bindingreagents may require more time to bind with the immobilized analytemolecule (or a protein-analyte complex) at the control line 130 than thetime it takes for the fluid material to flow by capillary action throughthe control line 130 into the wicking pad 120.

The third timer may allow enough time for the free labeled bindingreagents to bind with the immobilized antibody (in the sandwich assayformat) or with the immobilized analyte molecule/protein-analyte complex(in the competitive assay format) at the control line 130. Similarly, ina competitive assay format, after the expiration of the third timer, thebarrier 1635 may be removed (as shown by the arrow 1832) from betweenthe membrane 1616, and the wicking pad 120 to allow the fluid materialto flow from the membrane 1616 and the control line 130 into the wickingpad 120 by capillary action.

In some of the present embodiments, a separate linear actuator 525 (FIG.5), solenoid 605 (FIG. 6), or electromagnet 770 (FIG. 7) may be used toremove each of the barriers 135, 1630, and 1635 of FIG. 16. In some ofthe present embodiments, a magnet such as the magnet 405 (FIG. 4) may beattached to each barrier 135, 1630, and 1635 of FIG. 18 to pull thebarrier using a magnet such as magnet 545 (FIG. 5), magnet 615 (FIG. 6),or the core 710 (FIG. 7).

In some of the present embodiments, each barrier 135, 1630, and 1635 ofFIGS. 17-18 may have one or more holes such as the hole 805 (FIG. 8) topull the barrier using a hook such as the hook 905 of FIG. 9. In some ofthe present embodiments, each barrier 135, 1630, and 1635 of FIGS. 17-18may have a groove such as the groove 1005 (FIG. 10) to manually pull thebarrier.

Some of the present embodiments may include only one of the barriers135, 1630, or 1635 of FIGS. 16-18. Other embodiments may include any twoof the barriers 135, 1630, or 1635 of FIGS. 16-18. Some embodiments(such as the embodiment of FIGS. 16-18) may include all three barriers135, 1630, or 1635. In some embodiments, the number of timers may beequal to the number of barriers. Since the fluid flows downstream fromthe sample pad 150 towards the wicking pad 120, when a lateral flowassay device has two barriers, the barriers are removed starting withthe most upstream barrier followed by the next barrier downstream. Whenthe assay device has three barriers, the barrier 135 is removed first,followed by the barrier 1630, followed by the barrier 1635.

As described with reference to FIGS. 12 and 13, depending on the type ofthe material used for the conjugate pad 110, the membrane 115, and thebacking card, and/or the way pads 110 and 115 are placed on thecartridge bed, even when the barrier 135 is in place, some of fluidmaterial may leak from under the conjugate pad 110 (e.g., through thebacking card 140 and/or the cartridge bed) into the membrane 115. Withreference to FIGS. 17-27, the fluid material may leak from underneaththe membrane portion 1615 into the membrane portion 1616 even when thebarrier 1630 is in place. The fluid material may also leak fromunderneath the membrane portion 1616 into the wicking pad 120 even whenthe barrier 1635 is in place.

To prevent such leaks, some embodiments may include a permanent gap inthe cartridge bed and/or the backing card 140 in order to prevent thefluid material to leak from under the membrane portion 1615 into themembrane portion 1616 when the barrier 1630 is in place. Someembodiments may include a permanent gap in the cartridge bed and/or thebacking card 140 in order to prevent the fluid material to leak fromunder the membrane portion 1616 into the wicking pad 120 when thebarrier 1635 is in place.

FIG. 19 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device that includes one or morepermanent gaps in the backing card and/or the cartridge bed to preventthe leaking of the fluid material while the corresponding barrier(s)is/are in place, according to various aspects of the present disclosure.

With reference to FIG. 19, the cartridge bed 171, 173, and 174 may havea gap 1205 such that there is no cartridge bed under a portion of theconjugate pad 110 and the membrane 115 where the barrier 135 is betweenthe conjugate pad 110 and the membrane 115. In addition, there is a gap1210 in the backing card 140.

With further reference to FIG. 19, the cartridge bed 171, 173, and 174may have a gap 1910 such that there is no cartridge bed under a portionof the membrane 1615 and a portion of the membrane 1616 where thebarrier 1630 is located. The cartridge bed 171, 173, and 174 may have agap 1915 such that there is no cartridge bed under a portion of themembrane 1616 and a portion of the wicking pad 120 where the barrier1635 is located. As shown, the cartridge bed may be made of threeseparate sections 171, 173, and 174. The three sections of the cartridgebed may be secured on the housing of the lateral flow assay device 100.

With further reference to FIG. 19, there may be a gap 1920 in thebacking card 140 and/or a gap 1915 in the backing card 140. In theembodiments that the pads have individual backing cards, each backingcard may be made such that the backing card of the pads on the differentsides of a gap do not touch each other.

In the depicted embodiment, the backing cards do not cross over thecartridge bed gaps 1205, 1910, and 1915. In other embodiments, a portionof some or all backing cards may cross over a portion of a cartridge bedgap without touching the backing side of the adjacent pad on the otherside of the gap.

With reference to FIG. 19, depending on the type of the test performedby the lateral flow assay device, different embodiments of the lateralflow assay device may include one, two, or all three of the barriers135, 1630, and 1635. These embodiments may have the cartridge bed gaps1205, 1910, and 1915 for the corresponding barriers 135, 1630, and 1635.In addition to, or in lieu of the cartridge bed gaps 1205, 1910, and1915, some of these embodiments may include the backing card gaps 1210,1915, and 1929 for the corresponding barriers 135, 1630, and 1635.

With reference to FIGS. 1-19, the exemplary embodiments were describedwith reference to pulling the barrier 135 out of the cartridge 575. Inother embodiments, the barrier 135 may not be pulled out of thecartridge 575 at once. Instead, the barrier 135 may be partially pulledout and then pushed back in order to repeatedly bring the conjugate pad110 and the membrane 115 in touch with each other and then separate fromeach other. Repeatedly connecting and disconnecting the conjugate pad110 and the membrane 115 is a technical advantage that may be used tocontrol the flow of fluid material from the conjugate pad 110 into themembrane 115.

The number of times the barrier 135 is pulled out and pushed back intothe cartridge 575, the duration that the barrier 135 stays in or out ofthe cartridge 575, and the time between the pulling and pushing actionsmay control the amount of contact between the conjugate pad 110 and themembrane 115. The amount of contact between the conjugate pad 110 andthe membrane 115 may in turn be used by the processor 505 to control theflow time (the time it would take for the fluid material to travel thelength of the membrane 115, over the test line 125, and over the controlline 135 to reach the wicking pad 120).

As a first example, the electric motor 530 and the rotor 570 of FIG. 5may be controlled by the processor/comptroller 505 by repeatedlychanging the direction of the current through the electric motor,causing the linear moving shaft 540 to partially pull out the barrier135 out of the cartridge 575 and push beck the barrier 135 into thecartridge 575.

As a second example, the direction of current into the coil 660 of FIG.6 may be controlled by the processor/comptroller 505 by repeatedlychanging the direction of the current, causing the movable core 610 topartially pull out the barrier 135 out of the cartridge 575 and pushbeck the barrier 135 into the cartridge 575.

As a third example, the direction of current into the coil 705 of FIG. 7may be controlled by the processor/comptroller 505 by repeatedlychanging the direction of the current, causing the core 710 to partiallypull out the barrier 135 out of the cartridge 575 and push beck thebarrier 135 into the cartridge 575.

With reference to FIGS. 16-19, a similar technique may be used torepeatedly pull the barrier 1630 and/or the barrier 1635 partially outof the lateral flow assay cartridge (i.e., to partially pull out thebarrier from between the two pads that are separated by the barrier) andpushing the barrier back into the cartridge in order to control the timethe fluid material comes in contact with the test line 125, the time thefluid material comes in contact with the control line 130, and/or theflow rate across the flow path of the lateral flow assay device.Controlling the flow rate of the fluid as it passes over the test lineprovides the technical advantage of allowing enough binding time at thetest line location resulting in increased sensitivity for the test.Similarly, for the control line, the flow rate control provides thetechnical advantage of allowing enough binding time resulting instronger signal (color change) at the control line.

II. Using Removable Gaps in the Flow Path to Control the Flow and FlowTime

Some of the present embodiments may place a gap (instead of a physicalbarrier) in the barrier zone between the labeling zone and the capturezone. The gap may be placed between the conjugate pad and the membraneto separate the conjugate pad and the membrane until a timer expires.The lateral flow assay may include a housing (e.g., as described belowwith reference to FIGS. 20-21) that may initially (e.g., prior to thestart of a test and for a time period after the start of the test) holdone of the conjugate pad or the membrane pad, preventing the pads fromtouching each other. In other embodiments, the backing card of conjugatepad or the backing card of the membrane pad may be curved (e.g., asshown in FIGS. 32 and 33) to initially (e.g., prior to the start of atest and for a time period after the start of the test) prevent the padsfrom touching each other.

FIG. 20 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device 2000 that has a gap separatingthe labelling zone and the capture zone, according to various aspects ofthe present disclosure. The lateral flow assay device 2000 may besimilar to the lateral flow assay device 100 of FIG. 1, except that thelateral flow assay device 2000 may include a gap 2050 (instead of thephysical barrier 135 of FIG. 1) in the barrier zone 2003. The gap 2050separates (as shown by the dashed line 2020 and 2025) the conjugate pad110 and the membrane 115.

With reference to FIG. 20, the gap 2050 may be substantially occupied byair and may not allow the liquid material to flow from the conjugate pad110 into the membrane 115. Other components of the lateral flow assaydevice 2000 may be similar to the corresponding components of thelateral flow assay device 100 of FIG. 1. The lateral flow assay device2000 may include a housing, which is not shown in FIG. 20 forsimplicity.

In some of the present embodiments, the lateral flow assay may include ahousing (shown in FIG. 21) that may initially (e.g., prior to the startof a test and for a time period after the start of the test) hold theconjugate pad 110, preventing the conjugate pad 110 and the membrane 115from touching each other. The gap created between the conjugate pad 110and the membrane 115 may then be removed after a time period from thestart of the test.

FIG. 21 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device 2100 showing a cross section ofthe lateral flow assay device's housing before and after removing a gapbetween the labeling zone and the capture zone, according to variousaspects of the present disclosure. With reference to FIG. 21, theperspective shows a cross sectional view of the housing 170, 2105, and2106 across the surfaces 2108-2109. Similar to the housing 205 of FIG.2, the housing of FIG. 21 may include a sample port 210, an opening 215for viewing the test line 125, and an opening 220 for viewing thecontrol line 130. The figure as shown, includes two operational steps2101 and 2102. The housing 2105 may include a cartridge bed 170 forholding the lateral flow assay device's cartridge.

With reference to FIG. 21, step 2101 shows an initial state where thereis a gap 2050 (same as the gap 2050 of FIG. 20) between the conjugatepad 110 and the membrane 115. The gap may be maintained by a movablesection 2106 of the housing. Since FIG. 21 shows a cross sectional viewof the lateral flow assay device's 2100 housing, the figure shows across section of the movable section 2106 across the surface 2109. Themovable section 2106 may, therefore, substantially extend over the widthof the conjugate pad 110 along a surface delimited by line 2175, asshown in FIGS. 21 and 22.

FIG. 22 is a top elevational view of the housing of the lateral flowassay device of FIG. 21, according to various aspects of the presentdisclosure. With reference to FIG. 22, the top view of the housing2105-2106 shows the sample port 210, the test line 125 (partially hiddenby the housing), the control line 130 (partially hidden by the housing),the opening 215 for viewing the test line 125, the opening 220 forviewing the control line 130, and the movable section 2106 of thehousing 2105. FIG. 22 also shows the approximate extents of the samplepad 150, the conjugate pad 110, the membrane 115, and the wicking pad120.

With reference to FIG. 22, the lower portion of the movable section(shown by the dashed line 2175, which corresponds to the line 2175 ofFIG. 21) is attached to the conjugate pad (e.g., by an adhesivesubstance such as glue, resin, gum, etc.) and holds the conjugate pad110 separate from the membrane 115 (as shown in step 2101 of FIG. 21).With reference to FIG. 22, the lower portion 2175 of the movable section2106 may substantially extend over the width of the conjugate pad 110.

With further reference to FIG. 21, in some of the present embodiments, atimer may be programmed to allow time for the analyte (if any) in thesample fluid to bind with the labeled binding reagent on the conjugatepad 110. The timer may be started at the beginning of the test (e.g.,substantially at or around the same time as the sample fluid is appliedto the sample pad 150). The timer may be set such that enough time isallowed for the sample fluid to flow from the sample pad 150 into theconjugate pad 110 and for the analyte (if any) in the sample fluid tobind with the labelled binding reagent on the conjugate pad 110.

After the timer expires, the gap 2050 may be removed from between theconjugate pad 110 and the membrane in order to fluidically connect theconjugate pad 110 in the labeling zone 102 to the membrane 115 in thecapture zone 104. After the conjugate pad 110 and the membrane 115 cometo contact with each other, the fluid material in the flow path may flowfrom the conjugate pad 110 into the membrane 115 by capillary action.

In step 2102 of FIG. 21, the gap 2050 may be removed (e.g., after theexpiration of the timer) from between the conjugate pad 110 and themembrane 115 by moving the movable section 2106 towards the membrane 115until the conjugate pad 110 and the membrane 115 come into contact witheach other. As a first example, the movable section 2106 may be movedtowards the membrane 115 using a linear actuator similar to the linearactuator 525 of FIG. 5 or a solenoid similar to the solenoid 605 of FIG.6. The linear moving shaft 540 of FIG. 5 may include a surface (e.g.,instead of the magnet 545) with a shape sufficient for pushing down themovable section 2106 (e.g., with a surface that may be smaller than theoutside surface 2190 of the movable section 2106 that is facing outsideof the lateral flow assay device 2100).

At the beginning of a test, the electric motor 530 of FIG. 5 may beconfigured to pull the linear moving shaft 545 towards the rotatingshaft 580, and the linear actuator 525 may be placed adjacent to thelateral flow assay device 2100 (FIG. 21) such that the surface 545 onthe shaft 540 contacts the outside surface 2190 (FIG. 21) of the movablesurface 2106.

After the time required for the analyte in the sample fluid to bind withthe labeled binding agents on the conjugate pad 110 elapses, theelectric motor 530 may receive a signal (e.g., from the processor 505,from a pushbutton, from a toggle switch, etc., as described above withreference to FIG. 5) to extend the linear moving shaft 545 away from therotating shaft 580 and towards the lateral flow assay device 2100. Asthe linear moving shaft 540 is extended towards the lateral flow assaydevice 100, the surface 545 on the linear moving shaft 540 pushes theexternal surface 2190 of the movable section 2106, causing the gap 2015to be removed from between the conjugate pad 110 and the membrane 115.

With reference to step 2102 of FIG. 21, the movable section 2106 maymove in the direction of the arrow 2195 until the surface of the movablesection 2106 that is attached to the conjugate pad 110 (e.g., thesurface that is delimited by the line 2175 of FIGS. 21 and 22) makescontact with the membrane 115 and removes (as shown by the arrow 2185)the gap from between the conjugate pad 110 and the membrane 115.

As a second example, the movable section 2106 of the housing 2105 may bepushed towards the membrane 115 using the solenoid 605 of FIG. 6. Forexample, the movable core 610 may include a surface 615 (e.g., insteadof the magnet 615) with a shape sufficient for pushing down the movablesection 2106 (e.g., with a surface that may be smaller than the outsidesurface 2190 of the movable section 2106 that is facing outside of thelateral flow assay device 2100).

At the beginning of a test, the solenoid 605 may be configured (e.g., bychanging the direction of electric current in the wire 650) to pull themovable core 610 towards the solenoid 605, and the solenoid 605 may beplaced adjacent to the lateral flow assay device 100 (FIG. 21) such thatthe surface 615 on the movable core 610 contacts the outside surface2190 (FIG. 21) of the movable surface 2106.

After the time required for the analyte in the sample fluid to bind withthe labeled binding agents on the conjugate pad 110 elapses, thecontroller circuit 630 may receive one or more signals (e.g., from theprocessor 505, a pushbutton, a toggle switch, etc., as described abovewith reference to FIG. 6) to extend the movable core 610 away from thesolenoid 605 and towards the lateral flow assay device 2100. As themovable core 610 is extended towards the lateral flow assay device 2100,the surface 615 on the movable core 610 may push the external surface2190 of the movable section 2106, causing the gap 2015 to be removedfrom between the conjugate pad 110 and the membrane 115.

As a third example, one or more magnets may be attached to the uppersurface 2190 of the movable section 2106 of the lateral flow assaydevice 2100. The core 710 of FIG. 7 may be placed next to the lateralflow assay device 2100 such that the cross section of the core 710touches the upper surface 2190 of the movable section 2106 while theswitch 750 is open. After the time required for the analyte in thesample fluid to bind with the labeled binding agents on the conjugatepad 110 115 elapses, the controller circuit 730 may receive one or moresignals (e.g., from the processor 505, a pushbutton, a toggle switch,etc., as described above with reference to FIG. 7) to close the switch750. The amount and the direction of the current on the wire 750 and thecoil 705 may be adjusted such that the magnetic field generated by thecore 710 may repel the magnet(s) on the surface 2190 and push themovable section 2106 in the direction of the arrow 2195 until theconjugate pad 110 comes into contact with the membrane 115. For example,the magnetic field generated by the core 710 may be of the same polarityas the magnet(s) on the surface 2190 in order for the magnets to repeleach other.

In some of the present embodiments, the lateral flow assay device'shousing may include one or more movable poles, pillars, rods, and/orsprings to hold the conjugate pad separate from the membrane to create agap between the conjugate pad and the membrane. FIG. 23 is a frontelevational view of one example embodiment of a portion of a lateralflow assay device 2300 that may use one or more posts or pillars tocreate a removable gap between the conjugate pad and the membrane,according to various aspects of the present disclosure.

With reference to FIG. 23, the lateral flow assay device 2300 mayinclude one or more holes (the cross section of one of the holes isshown as delimited by the lines 2305). The hole(s) may go through thecartridge bed 170, the backing card 140, and the membrane 115.

The lateral flow assay device 2300, in some of the present embodiments,may include one or more movable poles, pillars, rods, and/or springs2310 (referred to herein as the pole or the poles for simplicity). Eachmovable pole 2310 may go through a hole 2305 to create a gap 2050between the conjugate pad 110 and the membrane 115 by keeping theconjugate pad 110 at a distance from the membrane 115, as shown in FIG.23.

FIG. 24 is a top elevational view of one example embodiment of thelateral flow assay device of FIG. 23, according to various aspects ofthe present disclosure. With reference to FIG. 24, the lateral flowassay device's 2300 housing is not shown for simplicity. In the exampleof FIG. 24, the lateral flow assay device 2300 includes five holes 2305.In other embodiments, the lateral flow assay device may include anynumber of one or more holes 2305.

With reference to FIG. 24, there is a pole 2310 in each of the holes2305. In the example of FIG. 24, the holes 2305 and the poles 2310 havea circular cross section. In other embodiments, the holes 2305 and thepoles 2310 may have a triangular, a rectangular, a polygon, or anyarbitrary shape cross sections.

The poles 2310 may be made of any material (e.g., plastic, metal, glass,etc.) that is capable of holding the conjugate pad 110 separate from themembrane 115 and do not react with the fluid material in the fluid flow.In some of the present embodiments, the poles 2310 may be attached tothe conjugate pad 110 by an adhesive substance (e.g., glue, resin, gum,etc.). In other embodiments, the poles 2310 may press against theconjugate pad 110 in order to keep the conjugate pad 110 separate fromthe membrane 115.

In some of the present embodiments, a timer may be programmed to allowtime for the analyte (if any) in the sample fluid to bind with thelabeled binding reagent on the conjugate pad 110. At the beginning of atest, the poles 2310 may be at the position shown in FIG. 23 to keep theconjugate pad 110 separate from the membrane 115. The gap 2050 may besubstantially filled by air and may prevent the fluid material in thefluid flow to move from the conjugate pad 110 into the membrane 115.

After the timer expires, the poles 2310 of FIGS. 23-24 may be pulled tobring the conjugate pad 110 into contact with the membrane 115. FIG. 25is a front elevational view of one example embodiment of a portion of alateral flow assay device 2300 after the gap between the conjugate padand the membrane is removed, according to various aspects of the presentdisclosure.

With reference to FIG. 25, the pole(s) 2310 are pulled in the directionof the arrow 2540 until the conjugate pad 110 and the membrane 115 comein contact with each other to allow the fluid material in the flow pathto flow from the conjugate pad 110 into the membrane 115 by capillaryact.

In some of the present embodiments, one or more pieces of magnet 2550(FIG. 25) may be attached to the poles 2310 of FIGS. 23-25 on thesurface of the poles that is facing outside of the housing 2505. Thepoles 2310 may be pulled down using a linear actuator similar to thelinear actuator 525 (as described above with reference to FIG. 5 forpulling the barrier 135), a solenoid similar to the solenoid 606 (asdescribed above with reference to FIG. 6 for pulling the barrier 135),or an electromagnet 770 (as described above with reference to FIG. 7 forpulling out the barrier 135).

For example, with reference to FIG. 5, at the beginning of a test, theelectric motor 530 may be configured to extend the linear moving shaft545 away from the rotating shaft 580, and the linear actuator 525 may beplaced adjacent to the lateral flow assay device 2300 (FIG. 25) suchthat the magnet(s) 545 on the shaft 540 may contact the magnet(s) 2550(FIG. 25) on the pole 2550. In the embodiments that the lateral flowassay device 2300 includes more than one pole 2310, the magnet 545 onthe shaft 540 may be large enough to make contact with the magnet 2550of all poles 2310. Alternatively, there may be multiple magnets 545 onthe shaft 540 to come in contact with the magnets on the poles 2550.

After the time required for the analyte (if any) in the sample fluid tobind with the labeled binding agents on the conjugate pad 110 elapses,the electric motor 530 may receive a signal to pull the linear movingshaft 545 back towards the rotating shaft 580 and away from the lateralflow assay device 2300. As the linear moving shaft 540 is pulled awayfrom the lateral flow assay device 2300, the magnet(s) 545 on the linearmoving shaft 540 pull(s) the magnet(s) 2550 (which is firmly attached tothe pole(s) 2310), causing the pole(s) 2310 to move in the direction ofthe arrow 2540 until the conjugate pad 110 comes in contact with themembrane 115. The magnets 545 and 2550 may have the polarities (e.g.,opposite polarities to attract each other) and enough magnetic force toallow them to connect to each other (e.g., by magnetic force) and tocontinue connecting to each other while the pole 2310 is being pulledthrough the hole 2305. After the conjugate pad 110 comes in contact withthe membrane 115, the gap 2050 of FIG. 23 is removed and the fluid mayflow from the conjugate pad 110 into the membrane 115 by capillary act.

The pole(s) 2310 may be pulled using the solenoid 605 of FIG. 6. Withreference to FIG. 6, at the beginning of a test, the solenoid 605 may beconfigured to extend the movable core 610 away from the solenoid 605,and the solenoid 605 may be placed adjacent to the lateral flow assaydevice 2300 (FIG. 25) such that the magnet(s) 615 on the movable core610 may contact the magnet 2550 (FIG. 25) on the pole 2550. In theembodiments that the lateral flow assay device 2300 includes more thanone pole 2310, the magnet 615 on the movable core 610 may be largeenough to make contact with the magnet 2550 of all poles 2310.Alternatively, there may be multiple magnets 615 on the movable core 610to come in contact with the magnets on the poles 2550.

After the time required for the analyte (if any) in the sample fluid tobind with the labeled binding agents on the conjugate pad 110 elapses,the controller circuit 630 may receive a signal to pull the movable core610 back towards the solenoid 605 and away from the lateral flow assaydevice 2300. As the movable core 610 is pulled away from the lateralflow assay device 2300, the magnet(s) 615 on the movable core 610 maypull the magnet(s) 2550 (which is/are firmly attached to the pole(s)2310), causing the pole(s) 2310 to move in the direction of the arrow2540 until the conjugate pad 110 comes in contact with the membrane 115.The magnets 615 and 2550 may have the polarities (e.g., oppositepolarities to attract each other) and enough magnetic force to allowthem to connect to each other (e.g., by magnetic force) and to continueconnecting to each other while the pole 2310 is being pulled through thehole 2305. After the conjugate pad 110 comes in contact with themembrane 115, the gap 2050 of FIG. 23 is removed and the fluid may flowfrom the conjugate pad 110 into the membrane 115 by capillary act.

The pole(s) 2310 may be pulled using the electromagnet 770 of FIG. 7.The core 710 of FIG. 7 may be placed next to the lateral flow assaydevice 2300 (FIG. 25) such that the cross section of the core 710 is adistance “d2” away from the magnet 2550 while the switch 750 is open.The distance “d2” may be substantially the same as the height of the gapbetween the conjugate pad 110 and the membrane 115 (e.g., the distancerequired to pull the conjugate pad 110 towards the membrane 115) inorder for the conjugate pad 110 and the membrane 115 to contact eachother.

After the time required for the analyte (if any) in the sample fluid tobind with the labeled binding agents on the conjugate pad 110 elapses,the controller circuit 730 may receive one or more signals (e.g., fromthe processor 505, a pushbutton, a toggle switch, etc., as describedabove with reference to FIG. 7) to close the switch 750. The amount andthe direction of the current on the wire 750 and the coil 705 may beadjusted such that the magnet generated by the core 710 may attract themagnet(s) 2550 on the pole(s) 2310 and pull the pole(s) 2310 in thedirection of the arrow 2540 until the conjugate pad 110 comes intocontact with the membrane 115. For example, the magnet generated by thecore 710 may be of the opposite polarity as the magnet(s) 2550 in orderfor the magnets to attract each other. After the conjugate pad 110 comesin contact with the membrane 115, the gap 2050 of FIG. 23 is removed andthe fluid may flow from the conjugate pad 110 into the membrane 115 bycapillary act.

FIG. 26 is a flowchart illustrating an example process 2600 for removinga gap that separates the labeling and capture zones of a lateral flowassay device, according to various aspects of the present disclosure. Insome of the present embodiments, the process 2600 may be performed by aprocessor 505 (FIGS. 5-7).

With reference to FIG. 26, the process 2600 may send (at block 2605) oneor more signals to a device to adjust the position of the device withrespect to the lateral flow assay device 2300 (FIGS. 23-25) and/or toset up the device to remove the gap 2050 of the lateral flow assaydevice 2300.

As a first example, the processor 505 (as described above with referenceto FIGS. 5 and 21-22) may send one or more signals to the electric motor530 to rotate and cause the rotational to linear movement converter 535to move the linear moving shaft 540 a predetermined distance in order tomake a contact between the linear moving shaft 540 and the upper surface2190 of the movable section 2106 of the housing 2105.

As a second example, the processor 505 (as described above withreference to FIGS. 6 and 21-22) may send one or more signals to thecontroller circuit 630 to move the movable core 610 a predetermineddistance in order to make a contact between the movable core 610 and theupper surface 2190 of the movable section 2106 of the housing 2105. As athird example, the processor 505 (as described above with reference toFIGS. 7 and 21-22) may send one or more signals to the controllercircuit 730 to turn off the switch 750 and prevent the core 710 to actas a magnet while the core 710 is contacting the top surface 2190 of themovable section 2116.

As a fourth example, the processor 505 of FIG. 5 may send one or moresignals to the electric motor 530 to rotate the rotating shaft 580 tocause the linear moving shaft 540 to move such that the magnet(s) 545 onthe linear moving shaft 540 come(s) in contact with the magnet(s) 2550(FIG. 25) on pole(s) 2310.

As a fifth example, the processor 505 of FIG. 6 may send one or moresignals to the controller circuit 630 to adjust the electric current inthe wire 650 and the coil 660 such that the magnet(s) 615 on the movablecore 610 come(s) in contact with the magnet(s) 2550 (FIG. 25) on pole(s)2310. As a third example, the processor 505 of FIG. 7 may send one ormore signals to the controller circuit 730 to turn off the switch 750 inorder for the core 710 not to act as a magnet.

As a sixth example, the processor 505 (as described above with referenceto FIGS. 7 and 23-25) may send one or more signals to the controllercircuit 730 to turn off the switch 750 and prevent the core 710 to actas a magnet while the core 710 is kept at a distance “d2” from themagnet(s) 2550 on the pole(s) 2310.

With further reference to FIG. 26, the process 2600 may receive (atblock 2610) a signal that includes a value to set a timer for removingthe barrier. The signal, in some embodiments, may include a value thatindicates the amount of time in a predetermined unit of time (e.g.,hours, minutes, seconds, milliseconds, microseconds, etc.). The signal,in some embodiments, may include a value and a unit of time. In someembodiments, the process 2600 may receive, at the processor 505 (FIGS.5-7), a signal that includes the timer value from the client device 515.In some embodiments, the processor 505 may be associated with andcommunicatively coupled to a user interface including a keyboard and adisplay. In these embodiments, the process 2600 may receive, at theprocessor 505, the signal that includes the timer value from thekeyboard associated with the processor.

With continued reference to FIG. 26, the process 2600 may then set (atblock 2615) set a timer to expire after a time period that is identifiedby the received value. For example, the processor 505 may set aninternal timer to expire after a time period determined by the receivedtimer value. The process 2600 may then determine (at block 2620) whetherto start the timer.

In some of the present embodiments, the process 2600 may receive asignal to start the timer, which is different that the signal thatincludes the timer value. For example, the client device 515 (FIGS. 5-7)may receive a signal through the application executing on the clientdevice 515 indicating the start of the test. The process 2600 may thenreceive a signal, at the processor 505, from the client device 515indicating the start of the test. Alternatively, the process 2600 mayreceive the signal after a physical switch (e.g., a push button or atoggle switch) that is communicatively coupled to the processor 505 isactivated to generate the signal. In some of the present embodiments,the process 2600 may start the timer as soon as the timer value is set(at block 2615). These embodiments may bypass block 2620.

When the process 1100 determines (at block 2620) that the timer shouldnot be started, the process 2600 may proceed back to block 2620.Otherwise, the process 2600 may start (at block 2625) the timer. Theprocess 2600 may then determine (at block 2630) whether the timer hasexpired. When the process 2600 determines (at block 2630) that the timerhas not expired, the process 2600 may proceed back to block 2630 to waitfor the timer to expire.

Otherwise, the process 2600 may send (at 2635) one or more signals toremove the gap by bringing together the labeling and capture zones ofthe lateral flow assay device. The process 2600 may then end. As a firstexample, as described above with reference to FIGS. 5 and 21-22, theprocessor 505 may send one or more signals to the electric motor 530 torotate and cause the rotational to linear movement converter 535 to movethe linear moving shaft 540 a predetermined distance in order to movethe movable section 2106 of the housing 2105 in the direction of thearrow 2195 in order to make a contact between the conjugate pad 110 andthe membrane 115.

As a second example, as described above with reference to FIGS. 6 and21-22, the processor 505 may send one or more signals to the controllercircuit 630 to change the direction of the electric current in the wire650 and cause the movable core 610 to move a predetermined distance inorder to move the movable section 2106 of the housing 2105 in thedirection of the arrow 2195 in order to move the movable section 2106 ofthe housing 2105 in the direction of the arrow 2195 and make a contactbetween the conjugate pad 110 and the membrane 115.

As a third example, as described above with reference to FIGS. 7 and21-22, the processor 505 may send one or more signals to the controllercircuit 730 to close the switch 750 and cause the core 710 to act as amagnet and repel the magnet(s) on the top surface 2190 of the movablesection 2116 in order to move the movable section 2106 of the housing2105 in the direction of the arrow 2195 and make a contact between theconjugate pad 110 and the membrane 115.

As a fourth example, as described above with reference to FIGS. 5 and23-25, the processor 505 may send one or more signals to the electricmotor 530 to rotate and cause the rotational to linear movementconverter 535 to move the linear moving shaft 540 a predetermineddistance in order to move the pole(s) 2310 in the direction of the arrow2540 (FIG. 25) in order to make a contact between the conjugate pad 110and the membrane 115. As a fifth example, as described above withreference to FIGS. 6 and 23-25, the processor 505 may send one or moresignals to the controller circuit 630 to change the direction of theelectric current in the wire 650 and cause the movable core 610 to movea predetermined distance in order to move the pole(s) 2310 in thedirection of the arrow 2540 (FIG. 25) to make a contact between theconjugate pad 110 and the membrane 115.

As a sixth example, as described above with reference to FIGS. 7 and23-25, the processor 505 may send one or more signals to the controllercircuit 730 to close the switch 750 and cause the core 710 to act as amagnet and attract the magnet(s) 2550 on the pole(s) 2310 in order tomove the pole(s) 2310 in the direction of the arrow 2540 (FIG. 25) tomake a contact between the conjugate pad 110 and the membrane 115.

Some of the present embodiments may place gaps (instead of a physicalbarriers) between different components of the lateral flow assay device.In addition to, or in lieu of, a gap between the labelling zone and thecapture zone, some of the present embodiments may have one or more gapsat other locations to provide additional time for the fluid material inthe fluid flow to have additional time to bind with the immobilizedmolecules at the test line and/or at the control line. In some of theseembodiments, the membrane may be made of several separate pieces (asoppose to one continuous piece of material). The gaps may besubstantially filled with air.

FIG. 27 is an upper front perspective view of one example embodiment ofa portion of a lateral flow assay device 2700 with multiple gapsseparating different components of the lateral flow assay device,according to various aspects of the present disclosure. The lateral flowassay device 2700 may include a housing that is not shown in FIG. 27 forsimplicity. The lateral flow assay device 2700 may be similar to thelateral flow assay device 1600 of FIG. 16, except that the lateral flowassay 2700 may include gaps (instead of the physical barriers) toseparate different components of the lateral flow assay device 2700.

With reference to FIG. 27, the gap 2015 between the conjugate pad 110and the membrane 1615 is substantially similar to the gap 2015 of FIG.20. The lateral flow assay device 2700 may include a gap 2750 separatingthe membranes 1615 and 1616 (as shown by the dashed lines 2751-2752)that may prevent fluid flow from the membrane 1615 and the test line 125into the membrane 1616. The lateral flow assay device 2700 may include agap 2755 separating the membrane 1616 and the wicking pad 120 (as shownby the dashed lines 2756-2757) that may prevent fluid flow from themembrane 1616 and the control line 130 into the wicking pad 120.

In some of the present embodiments, the lateral flow assay may include ahousing that may initially (e.g., prior to the start of a test and for atime period after the start of the test) hold different components ofthe lateral flow assay device separate from each other to maintain thegaps 2050, 2750, and 255. FIG. 28 is an upper front perspective view ofone example embodiment of a portion of a lateral flow assay deviceshowing a cross section of the lateral flow assay device's housingbefore and after removing multiple gaps, according to various aspects ofthe present disclosure.

With reference to FIG. 28, the perspective shows a cross sectional viewof the housing 2805-2308 across the surfaces 2811-2314. Similar to thehousing of FIG. 17, the housing 2805-2308 of FIG. 28 may include asample port 1710, an opening 1715 for viewing the test line 125, and anopening 1720 for viewing the control line 130.

The figure as shown, includes two operational steps 2801 and 2802. Withreference to FIG. 28, step 2801 shows an initial state where there maybe a gap 2050 (same as the gap 2050 of FIG. 17) between the conjugatepad 110 and the membrane 1615. The gap 2050 may be maintained by amovable section 2806 of the housing. There may be a gap 2750 (same asthe gap 2750 of FIG. 17) between the membrane 1615 and the membrane1616. The gap 2750 may be maintained by a movable section 2807 of thehousing. There may be a gap 2755 (same as the gap 2755 of FIG. 17)between the membrane 1616 and the wicking pad 120. The gap 2755 may bemaintained by a movable section 2106 of the housing. The gap 2755 may bemaintained by a movable section 2808 of the housing.

Since FIG. 28 shows a cross sectional view of the lateral flow assaydevice's 2700 housing, the figure shows a cross section of the movablesections 2806, 2807, and 2808 across the surfaces 2812, 2813, and 2814,respectively. The movable sections 2806, 2807, and 2808 maysubstantially extend over the width of the lateral flow assay device2700 similar to what was described above with reference to FIGS. 21 and22 for section 2106.

With reference to step 2802 of FIG. 28, some of the present embodimentsmay use several timers for removing the gaps 2050, 2750, and 2755 ofFIG. 28. For example, a first timer may be set to allow the analyte (ifany) in the sample fluid to bind with the labeled binding agents on theconjugate pad 110. After the expiration of the first timer, the gap 2050may be removed by moving (as shown by the arrow 2891) the movablesection 2806 towards the membrane 1615 until the conjugate pad 110 andthe membrane 1615 come into contact with each other. After the conjugatepad 110 and the membrane 1615 come to contact with each other, the fluidmaterial in the flow path may flow from the conjugate pad 110 into themembrane 1615 by capillary action.

With continued reference to FIG. 28, after the expiration of the firsttimer, a second timer may be started to determine the time for removingthe gap 2750. In some of the present embodiments, the labelledimmunocomplex in a sandwich format assay may require more time to bindwith the immobilized binding reagent at the test line than the time ittakes for the fluid material to flow by capillary action through thetest line 125 into the membrane 1616. The second timer may allow enoughtime for the binding of the labelled immunocomplex with the immobilizedbinding reagent at the test line. Similarly, in a competitive assayformat, the labelled binding reagent in the fluid may require more timeto bind with the immobilized analyte/protein-analyte complex in the testline. The second timer may allow enough time for the binding of thelabelled binding reagent with the immobilized binding reagent at thetest line.

After the expiration of the second timer, the gap 2750 may be removed bymoving (as shown by the arrow 2892) the movable section 2807 towards themembrane 1615 until the membrane 1616 and the membrane 1615 come intocontact with each other. After the membrane 1616 and the membrane 1615come to contact with each other, the fluid material in the flow path mayflow from the membrane 1615 into the membrane 1616 by capillary action.

After the expiration of the second timer, a third timer may be startedto determine the time for removing the gap 2755. In some of the presentembodiments, the free labeled binding reagents may require more time tobind with the immobilized antibody in a sandwich format assay at thecontrol line than the time it takes for the fluid material to flow bycapillary action through the control line 130 into the wicking pad 120.Similarly, in a competitive assay format, the free labeled bindingreagents may require more time to bind with the immobilized analytemolecule (or a protein-analyte complex) at the control line 130 than thetime it takes for the fluid material to flow by capillary action throughthe control line 130 into the wicking pad 120.

The third timer may allow enough time for the free labeled bindingreagents to bind with the immobilized antibody (in the sandwich assayformat) or with the immobilized analyte molecule/protein-analyte complex(in the competitive assay format) at the control line 130. Similarly, ina competitive assay format. After the expiration of the third timer, thegap 2755 may be removed by moving (as shown by the arrow 2893) themovable section 2808 towards the membrane 1616 until the wicking pad 120and the membrane 1616 come into contact with each other to allow thefluid material to flow from the membrane 1616 and the control line 130into the wicking pad 120 by capillary action.

The movable sections 1250, 2750, and 2755 of the housing may be moved bymechanisms such as a linear actuator 525 (FIG. 5), a solenoid 615 (FIG.6), or an electromagnet 770 (FIG. 7) as described above with referenceto the lateral flow assay 2100 of FIG. 21.

Some of embodiments may include a housing with a one or more sets ofholes. Each hole may include a pole for maintaining one of the gaps inthe barrier zone of the lateral flow assay device. FIG. 29 is a frontelevational view of one example embodiment of a portion of a lateralflow assay device 2900 that may use multiple posts or pillars to createremovable gaps between different components of the lateral flow assaydevice, according to various aspects of the present disclosure.

As shown, the lateral flow assay device 2900 may include one or more setof holes (the cross section of one of the holes is shown as delimited bythe lines 2305, 2906, and 2907). The lateral flow assay device 2900, insome of the present embodiments, may include one or more sets of movablepoles (or pillars) 2310, 2911, and 2912. Each movable pole 2310 may gothrough a hole 2305 to create the gap 2050 between the conjugate pad 110and the membrane 1615 by keeping the conjugate pad 110 at a distancefrom the membrane 1615, as shown in FIG. 29.

Each movable pole 2911 may go through a hole 2906 to create the gap 2750between the membrane 1615 and the membrane 1616 by keeping the membrane1616 at a distance from the membrane 1615, as shown in FIG. 29. Eachmovable pole 2912 may go through a hole 2907 to create the gap 2755between the membrane 1616 and the wicking pad 120 by keeping the wickingpad 120 at a distance from the membrane 1616, as shown in FIG. 29.

FIG. 30 is a top elevational view of one example embodiment of thelateral flow assay device of FIG. 29, according to various aspects ofthe present disclosure. With reference to FIG. 30, the lateral flowassay device's 2700 housing is not shown for simplicity. In the exampleof FIG. 30, the lateral flow assay device 2700 includes three sets ofthree holes 2305, 2911, and 2912. In other embodiments, the lateral flowassay device may include any number of holes in each set of holes 2305,2906, and 2907. In the example of FIG. 29, the holes 2305, 2906, and2907 and the poles 2310, 2911, and 2912 have a circular cross section.In other embodiments, the holes 2305, 2906, and 2907 and the poles 2310,2911, and 2912 may have a triangular, a rectangular, a polygon, or anyarbitrary shape cross sections. The poles 2310, 2911, and 2912 may bemade of any material (e.g., plastic, metal, glass, etc.) that is capableof holding the components of the lateral flow assay device separate fromeach other (as described below) and do not react with the fluid materialin the fluid flow.

With reference to FIG. 30, the holes 2305 and the poles 2310 aresubstantially similar to the holes 2305 and the poles 2310 of FIG. 24.In some of the present embodiments, the poles 2310 may be attached tothe conjugate pad 110 by an adhesive substance (e.g., glue, resin, gum,etc.) to keep the conjugate pad 110 separate from the membrane 1615. Inother embodiments, the poles 2310 may press against the conjugate pad110 in order to keep the conjugate pad 110 separate from the membrane1615.

With further reference to FIG. 29, each pole 2911 may go through a hole2906. Each pole 2911 may be attached to the membrane 1616 by an adhesivesubstance (e.g., glue, resin, gum, etc.) to keep the membrane 1616separate from the membrane 1615. In other embodiments, the poles 2911may press against the membrane 1616 in order to keep the membrane 1616separate from the membrane 1615.

With continued reference to FIG. 29, each pole 2912 may go through ahole 2907. Each pole 2912 may be attached to the wicking pad 120 by anadhesive substance (e.g., glue, resin, gum, etc.) to keep the wickingpad 120 separate from the membrane 1616. In other embodiments, the poles2912 may press against the wicking pad 120 in order to keep the wickingpad 120 separate from the membrane 1616.

FIG. 31 is a front elevational view of one example embodiment of aportion of a lateral flow assay device 2900 after several gaps areremoved between different components of the lateral flow assay device,according to various aspects of the present disclosure. With referenceto FIG. 31, some of the present embodiments may use several timers forremoving the gaps 2050, 2750, and 2755. For example, a first timer maybe set to allow the analyte (if any) in the sample fluid to bind withthe labeled binding agents on the conjugate pad 110. After theexpiration of the first timer, the gap 2050 may be removed by pullingdown the pole(s) 2310 (as shown by the arrow 3131) until the conjugatepad 110 and the membrane 1615 come into contact with each other. Afterthe conjugate pad 110 and the membrane 1615 come to contact with eachother, the fluid material in the flow path may flow from the conjugatepad 110 into the membrane 1615 by capillary action.

With continued reference to FIG. 31, after the expiration of the firsttimer, a second timer may be started to determine the time for removingthe gap 2750. In some of the present embodiments, the labelledimmunocomplex in a sandwich format assay may require more time to bindwith the immobilized binding reagent at the test line than the time ittakes for the fluid material to flow by capillary action through thetest line 125 into the membrane 1616. The second timer may allow enoughtime for the binding of the labelled immunocomplex with the immobilizedbinding reagent at the test line. Similarly, in a competitive assayformat, the labelled binding reagent in the fluid may require more timeto bind with the immobilized analyte/protein-analyte complex in the testline. The second timer may allow enough time for the binding of thelabelled binding reagent with the immobilized binding reagent at thetest line.

After the expiration of the second timer, the gap 2750 may be removed bypulling down the pole(s) 2911 (as shown by the arrow 3132) until themembrane 1616 and the membrane 1615 come into contact with each other.After the membrane 1616 and the membrane 1615 come to contact with eachother, the fluid material in the flow path may flow from the membrane1615 into the membrane 1616 by capillary action.

After the expiration of the second timer, a third timer may be startedto determine the time for removing the gap 2755. In some of the presentembodiments, the free labeled binding reagents may require more time tobind with the immobilized antibody in a sandwich format assay at thecontrol line than the time it takes for the fluid material to flow bycapillary action through the control line 130 into the wicking pad 120.Similarly, in a competitive assay format, the free labeled bindingreagents may require more time to bind with the immobilized analytemolecule (or a protein-analyte complex) at the control line 130 than thetime it takes for the fluid material to flow by capillary action throughthe control line 130 into the wicking pad 120.

The third timer may allow enough time for the free labeled bindingreagents to bind with the immobilized antibody (in the sandwich assayformat) or with the immobilized analyte molecule/protein-analyte complex(in the competitive assay format) at the control line 130. Similarly, ina competitive assay format. After the expiration of the third timer, thegap 2755 may be removed by pulling down the pole(s) 2912 (as shown bythe arrow 3133) until the wicking pad and the membrane 1616 come intocontact with each other to allow the fluid material to flow from themembrane 1616 and the control line 130 into the wicking pad 120 bycapillary action.

The poles 2310, 2911, and 2912 may be moved by mechanisms such as alinear actuator 525 (FIG. 5), a solenoid 615 (FIG. 6), or anelectromagnet 770 (FIG. 7) as described above with reference to thelateral flow assay 2300 of FIGS. 23-24. Some of the present embodimentsmay include only one of the gaps 2015, 2750, or 2755 of FIG. 27. Otherembodiments may include any two of the gaps 2015, 2750, or 2755 of FIG.27. Some embodiments (such as the embodiment of FIG. 27) may include allthree gaps 2015, 2750, or 2755. In some embodiments, the number oftimers to remove the gaps may be equal to the number of gaps. Since thefluid flows downstream from the sample pad 150 towards the wicking pad120, when a lateral flow assay device has two gaps, the gaps are removedstarting with the most upstream gap followed by the next gap downstream.When the assay device has two or three gaps, the existing gaps areremoved in the following order: gap 2015 is removed first, followed bythe gap 2750, followed by the gap 2755.

In some embodiments, the backing card of conjugate pad or the backingcard of the membrane pad may be curved to initially (e.g., prior to thestart of a test and for a time period after the start of the test)prevent the pads from touching each other. FIG. 32 is a front elevationview of one example embodiment of a portion of a lateral flow assaydevice 3200 that removes gaps by a spring mechanism, according tovarious aspects of the present disclosure. FIG. 33 is a functional blockdiagram illustrating one example embodiment of the lateral flow assaydevice of FIG. 32, according to various aspects of the presentdisclosure.

With reference to FIGS. 32 and 33, the lateral flow assay device 3200may include a housing 3230, a sample input port 3220, and a clear cover3205 to view the results on the test line 125 and the control line 130.The disposable cartridge of the lateral flow assay device 3200 mayinclude an NFC chip 590. The NFC chip 590 may identify the test andother parameters and information related to the test, including but notlimited to, the conjugation time on the conjugate pad and the flow time,which is the time it should take for the sample fluid to flow from thepoint the sample is applied through the sample input port 3220 to thewicking pad 120.

The lateral flow assay device 3200 may include an NFC reader (notshown), such as the NFC reader 595 of FIGS. 5-7. When the cartridge isplaced in the lateral flow assay device, the NFC reader automaticallydetects the presence of the NFC tag 590, reads the information andparameters of the test, and sends the information and parameters to aprocessor or controller (e.g., the processor/controller 505 of FIG. 33)of the lateral flow device 3200. The processor/controller may use theinformation and the parameters to perform the test. Theprocessor/controller may display a portion of the information orparameters on a display of the lateral flow assay device (e.g., on adisplay of the UI 550 of FIG. 33). The processor/controller may send aportion of the information or parameters to an electronic deviceexternal to the lateral flow assay device.

When the sample is blood and the test needs plasma separation, thedisposable cartridge may include the optional plasma separator filter1420. The plasma separator filter 1420 may be located over the conjugatepad 110 between the sample input port 3220 and the conjugate pad 110.Once the sample is added, a start button either on the device's UI(e.g., on a keyboard or a touch screen) or a button on the device'shousing may be pushed to start the test. This may also start a timer forthe conjugation time. Alternatively, a signal to start the test may bereceived by the processor of the lateral flow assay device 3200 from anelectronic device (e.g., a client device) external to the lateral flowassay device 3200.

After the sample is applied, the sample flows on the conjugate pad 110and starts mixing and interacting with the conjugate chemicals on theconjugate pad 110. As shown in FIGS. 32 and 33, a gap 3291 may initiallybe maintained between the conjugate pad 110 and the membrane 115.Similarly, a gap 3292 may initially be maintained between the membrane115 and the wicking pad. The gaps 3291 and 3292 may be substantiallyfilled by air. Accordingly, unlike the conventional flow lateral assaycartridges and systems, the conjugate pad 110 is not touching themembrane 115. The conjugate pad 110 is held away from the membrane 115by the spring 3241 (e.g., a thin flat metal, such as steel, with a bend3271 at the base 3272) that is attached to the clear backing 3211 of theconjugation pad 110. Although a clear backing may be used, especiallyfor the membrane, so the colored test and control lines may be seen fromboth side, it should be understood that at least a portion of thebacking, in some embodiments, may be opaque. The conjugate pad 110, thebacking 3211, and the spring 3241 may be connected to the housing 3230by a pin or screw 3288. The spring 3241 may be anchored to the housing3230 by a pin or screw 3289.

Once the specified conjugation time is lapsed (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.), the solenoid 3251 may beactivated by a command from the processor/controller 505 (FIG. 33),which may cause the solenoid shaft 3221 to push on the spring 3241 andmake the conjugate pad 110 touch the membrane 115 to allow the flow ofthe fluid material from the conjugate pad 110 to the membrane 115.

The solenoid 3251 may function as a transducer that converts energy intolinear motion. The solenoid 3251 may include an electromagneticallyinductive coil 3365 (FIG. 33) that is wrapped around the movablesolenoid shaft (or armature) 3221. When an electric current passesthrough the wire 3360 of FIG. 33, a magnetic field is generated by thecoil 3365 that causes the moveable shaft 3221 to move in a linear line.By changing the direction of the current, the magnetic field is reversedthat causes the solenoid shaft (or armature) 3221 to move in theopposite direction. If a spring loaded solenoid is used, there may be noneed to reverse the direction of the current as removing the current(zero current) causes the solenoid to return to its original positionvia the spring on its shaft. The use of the spring loaded solenoidprovides the advantage that the spring loaded solenoid does not draw anycurrent and does not consume any energy in the off position, resultingin much longer battery life for battery-operated lateral flow assaydevices.

The solenoid 3251 may be repeatedly activated and deactivated to pushthe solenoid shaft 3221 against the spring 3241 to bring the conjugatepad 110 and the membrane 115 in touch with each other, followed bypulling the solenoid shaft 3221 away from the spring 3241 to cause thespring 3241 to separate the conjugate pad 110 from the membrane 115.Repeatedly connecting and disconnecting the conjugate pad 110 and themembrane 115 may be used to control the flow of fluid material from theconjugate pad 110 into the membrane 115.

The processor/controller 505 may generate signals (e.g., and withoutlimitations, a set of pulses) to activate the solenoid 3251 according toan algorithm. The processor may use three parameters to control the flowtime of the fluid from the time the sample fluid starts flowing at thebeginning of the membrane 115 (i.e., the intersection of the conjugatepad 110 and the membrane 115) to the time the fluid reaches the wickingpad 120. The three parameters are the number of times the conjugate padand the membrane pad are connected (or disconnected), the duration ofeach connections, and the duration of each disconnection (or the timebetween consecutive connection and disconnections).

The longer the duration of each connection, the more fluid istransferred from the conjugate pad 110 to the membrane 115. These threeparameters may be calculated by the processor 505 using an algorithm anda set of calibration tables or calibration curves. The algorithm inputmay be the desired conjugation time and flow time, which may be, forexample, programmed into the NFC tag 590 at manufacturing. The algorithminput may also include one or more parameters related to the papermaterial used in the cartridge pads, as described below.

The conjugation time may be controlled by a timer. The conjugate timemay be received by the processor (e.g., and without limitations, fromthe NFC chip 950, from a client device, from the UI 550, etc.). Theprocessor 505 may also receive a signal (e.g., and without limitations,from a client device, from the UI 550, from a switch or button on thelateral flow device's housing, etc.) indicating the start of the test.The processor 505 may measure the elapsed time since the start of thetest. After the elapse of the specified conjugation time from the startof the test, the processor 505 may activate the solenoid (or anelectromagnet, a servo, a linear actuator, or other mechanism used forbringing the conjugate pad and the membrane pad together).

Unlike the membrane 115, the test line 125, and the control line 130,the conjugate pad 110, in some embodiments, may not need any flow ratecontrol. The flow rate for the membrane pad and the flow time (which isthe time it takes for the solution to travel from one end of themembrane to the other) may be controlled by on-off cycling (pulsing) ofthe mechanism (e.g., and without limitations, the solenoid, theelectromagnet, the servo, the linear actuator) that brings the conjugatepad and the membrane pad together. The flow time may be controlled withthe time that the pads are connected (Tc) and the time that the pads aredisconnected (Td). The value of these parameters and the number of timesthe pads are connected and disconnected may be determined via analgorithm that uses calibration tables or calibration curves asdescribed below.

The calibration curves or tables may be generated by a number ofcontrolled experiments for the type of membrane paper material used bythe desired test to be performed by the lateral flow assay cartridge andthe lateral flow assay device. FIG. 34 illustrates an example of anumber of curves generated for a particular membrane paper material fora range of connection time (Tc) and disconnection time (Td) of theconjugate pad and the membrane, according to various aspects of thepresent disclosure. In order to generate the curves 3400, Tc and Td arevaried and the time it takes for the solution to travel from one end ofthe membrane pad 115 to the other is measured and recorded. This processmay be repeated for a large number (e.g., and without limitations, tens,hundreds, thousands, etc.) of Tc and Td values in a specified range.

The example of FIG. 34 shows curves that are generated for the values ofTc ranging from 160 milliseconds (mSec.) to 1000 mSec., and Td rangingfrom 1 Sec. to 8 Sec. The exemplary curves 3400 were generated for atotal of 56 points. The horizontal axis 3405 shows the values of Tc. Thevertical axis 3410 shows the flow time (in mSec.) as a function of theTc time for each of eight different values 3415 of Td used for thisparticular calibration operation (one curve is generated for each Td).

When a desired flow time is specified for a test that a cartridge ismade for, the algorithm uses the flow time value to calculate the properTc and Td from the calibration curves 3400. FIG. 35 illustrates anexample of selecting the connection and disconnection times of theconjugate and membrane pads for a specified flow time, according tovarious aspects of the present disclosure. In the example of FIG. 35,the specified flow time is 400 Seconds.

With reference to FIG. 35, the intersection points 3541-3544 of thehorizontal line 3550 representing the 400 Sec. time on the vertical axis3410 with the curves 3500 are calculated. For example, one or morecalibration tables may store the values corresponding to the curves 3400and the values in the table may be searched and/orinterpolated/extrapolated to identify the intersection points 3541-3544.

In the example of FIG. 35, points 3541-3544 correspond to the differentcombinations of (Tc, Td) pairs that may achieve the specified flow time.The algorithm may consider the slope of each curve at the intersectionpoints 3541-3544 and pick the one with the smallest slope as thatresults in the smallest variation around the selected Tc value. In thisexample, point 3544 may be picked that corresponds to Tc ofapproximately 308 mSec., and Td of 8 Sec. Once these values areselected, the number of times the connection and disconnection of theconjugate and membrane pads are to be repeated is calculated by dividingthe flow time by Tc+Td. It should be understood that the algorithmdescribed above for selecting the point on the curves 3400 is anexample. Other methods and algorithms may be devised to select thedesired parameters. As another two-step procedure, once the points onthe curves 3400 (e.g., the points 3541-3544 in FIG. 35) are calculated,another set of calibration experiments with more timing resolution maybe performed in a region of the interest around the points 3541-3544 torefine the parameters.

The more points are chosen for generating the calibration curves 3400,the more accurate the results of choosing the appropriate Tc and Td maybe. In the example of FIGS. 34-35, 56 points were used to demonstratethe process. For a better calibration, more points (e.g., and withoutlimitations, hundreds, thousands, etc.) may be used. The calibrationcurves 3400 may be generated once for each membrane type for eachmanufacturer of the membrane. Generating the curves 3400 and thecorresponding table(s), may not be a time consuming process given thatthe result are applicable to a very large number of cartridges.

The calibration process may be done by either the manufacturer of themembrane paper or the developer of the test cartridge. Once theappropriate parameters are determined for the particular test thecartridge is supposed to be made for, the parameters may be programmedinto the NFC chip on the cartridge. In the case of the stand-alonedisposable cartridges, these parameters may be programmed into thefirmware of the processor/controller embedded in the cartridge.Alternatively, the parameters may be stored on a network device that maybe downloaded to a client device. The client device may then transferthe parameters to the processor/controller of the lateral flow assaydevice prior to the start of a test.

If the lateral flow assay device cartridge also includes a flow controlmechanism between the wicking pad and the membrane pad (e.g., as shownin FIGS. 32 and 33), the flow control mechanism between the wicking padand the membrane pad may also have its Tc and Td parameters that mayeither use the same values as the Tc and Td for the mechanism betweenthe conjugate pad and the membrane or it may use its own independent Tcand Td values. In either case, the calibration curves may be generatedin a similar manner as described above where for the case of independentset of Tc, Td for the wicking pad the experiments may be more extensivein that there may be multiple curve sets to generate.

In membrane papers used in conventional lateral flow assay strips andcartridges not employing the flow control techniques described herein,the flow rate of the solution on the membrane paper varies with time andgets slower as the solution front moves away from the beginning stripwith time. Another technical advantage provided by the lateral flowassay device and cartridges of the embodiments disclosed herein, is thatthe values of Tc and Td may change for every cycle of connection anddisconnection of the pads and not necessarily be the same every cycle.It, therefore, is possible to control the shape of the flow rate curveand, if desired, even equalize it to become close to linear across thelength of the membrane.

Some of the present embodiments provide a cycle by cycle control of theflow rate of the fluid. A slower flow rate of the fluid over themembrane results in higher sensitivity for the test as a slower flowrate gives the solution fluid more time to bind to, and interact with,the reagents on the test and control lines as the solution fluid passesover the test and control lines which are on a narrow region on themembrane.

Since the present embodiments provide cycle by cycle control overconnecting and disconnecting of the conjugate pad and the membrane andprovide control over setting the values of Tc and Td, the lateral flowassay device may be configured to keep the flow rate at a higher speeduntil the fluid front reaches close to the test line and then change theTc and Td values to slow down the flow rate. This results in a fasteroverall test time without losing sensitivity. The values of Tc and Td tobe used for both the beginning of the flow and for slowing the flow ratedown when the fluid reaches near the test line may be determined fromcalibration curves similar to the calibration curves shown in FIGS.34-35 once those curves are generated for the particular membranematerial used in the test as was explained above. Since the distance ofthe test line from the beginning of the membrane and the rate set forthe beginning phase of the flow is known, the time it takes for thefluid front to get to a predetermined distance from the test line may becalculated. The processor/controller 505 controlling the lateral flowassay device may keep track of the time and may switch the flow to theslower rate at the right time (e.g., after a time period required forthe fluid to reach the predetermined distance from the test line). Thecycle by cycle control over connecting and disconnecting of theconjugate pad and the membrane may be applied to any of the embodimentsdescribed herein with reference to FIGS. 32-33 and 36-46.

Some of the present embodiments may compensate for the membranemanufacturing variabilities. One of the factors in manufacturing themembranes is the variability of the flow rate of the membrane from lotto lot. Using the flow control technology of the present embodiments,the flow rate may be set at a point slightly beyond where increase inthe sensitivity (e.g., making the flow rate of the fluid over themembrane slower to give the solution fluid more time to bind) issaturated and the material variability may have very minimal to noeffect if the flow rate is made slower. In this way, the test cartridgeproduct may have a smaller percent coefficient of variability (CV %).Where to set the optimum flow rate depends on the membrane materialselected and the test itself. For each test type and for a givenmembrane material, some embodiments generate the set of calibrationcurves and/or tables similar to what was described above with referenceto FIGS. 34-35. Using these curves and/or tables, a set of experimentsare conducted where the flow rate for each experiment is set from thecalibration curves, the test is performed, and the sensitivity of thetest is measured (e.g. by repeating the test for sequentially dilutedconcentration levels).

The flow rate is then set at a lower value and the tests are repeated tomeasure the sensitivity again. This process is continued until a pointis reached where there is no improvements in the sensitivity. The flowrate and the Tc and Td values corresponding to this saturation point arerecorded. The final flow rate set for the test is picked from thecalibration curves at a point slightly lower than this flow rate. Thisensures that any variations in manufacturing the selected membranematerial does not affect the sensitivity of the test as the selectedflow rate is always above the point where maximum gain in sensitivity isachieved. The process above may be done once during the manufacturing ofa given test type and the Tc and Td parameters are then fixed for volumeproduction for this particular test type and the membrane materialselected. The technique of compensating for the membrane manufacturingvariabilities may be applied to any of the embodiments described hereinwith reference to FIGS. 32-33 and 36-46.

Some embodiments compensate for the viscosity variations of the samplefluid. The flow rate of the membrane is also dependent on the viscosityof the sample fluid. Instead of changing the membrane material fordifferent sample fluids, some embodiments keep the material the same anduse the flow control technology described herein to determine parametersfor on-off cycling (pulsing) of the conjugate pad and/or the wicking padto compensate for the viscosity dependence. The optimum values of Tc andTd for a given viscosity are determined by a similar approach describedabove in generating the calibration curves for a given membrane andexperimentally finding the optimum sensitivity for the test type. Theseparameters may be loaded into the NFC tag of the cartridge and when theprocessor/controller 505 reads the NFC, the processor/controller 505sets up the correct parameters automatically. The technique ofcompensating for the viscosity variations may be applied to any of theembodiments described herein with reference to FIGS. 32-33 and 36-46.

With further reference to FIGS. 32 and 33, the processor 505 mayactivate and deactivate the solenoid 3251 as described above until thenumber of connection and disconnection of the pads required to achievethe flow time is achieved. The processor may then stop pulsing thesolenoid 3251 and may leave the solenoid 3251 at either engaged ordisengaged position depending on what the test specifies.

With continued reference to FIGS. 32 and 33, a gap 3292 may be initiallymaintained between the membrane 115 and the wicking pad 120. Unlike theconventional flow lateral assay cartridges and systems, the membrane 115is not touching the wicking pad 120. The membrane 115 may be held awayfrom the wicking pad 120 by the spring 3242 that is attached to thebacking 3213 of the wicking pad 120. The wicking pad 120, the backing3213, and the spring 3242 may be connected to the housing 3230 by a pinor screw 3293. The spring 3242 may be anchored to the housing 3230 by apin or screw 3294.

The solenoid 3252 may be used to attach and detach the wicking pad 120to the membrane 115 by a similar technique as described above withreference to the solenoid 3251. The processor 505 may start pulsing thesolenoid 3252 either at the same time as the solenoid 3251 or once thepulsing of the solenoid 3251 is completed. The latter approach may useless power.

The attaching and detaching of the wicking pad 120 and the membrane 115by the solenoid 3252 and the solenoid shaft 3222 may continue for acertain number of connection and disconnection (which may be determinedbased on the desired flow rate as described above) after the pulsing ofsolenoid 3251 is completed at which time the result of the test may beready for viewing through the clear cover 3205 and/or for reading viasensors such as, for example and without limitations, optical sensors.

Some lateral flow assay based tests may not need a wicking pad. Theembodiments of the lateral flow assay device 3200 that are used forthese test may not include the wicking pad 120 and the solenoid 3252.For some other tests, the wicking pad 120 may always be left connectedto the membrane. The embodiments of the lateral flow assay device 3200that are used for these tests may not include the solenoid 3252. Incartridges where both the conjugation pad 110 and the wicking pad 120have the spring mechanism as discussed above, the solenoid 3252 mayalways be activated and kept in a position to always attach the wickingpad 120 to the membrane 115 for the entire duration of the test if thatis what is desired and specified for the test (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.).

As shown in FIGS. 32 and 33, the springs 3241 and 3242 do not continueall the way to the tip 3296 of the conjugation pad and the tip 3297 ofthe wicking pad. There is a small portion of the pads 110 and 120 at thetips 3296 or 3297 that comes in contact with the membrane 115 when thespring 3241 or 3242 is pushed by the corresponding solenoid shaft 3251or 3252. With further reference to FIGS. 32 and 33, the position of thesolenoid shafts 3221 and 3222 on the springs 3241 and 3242 is at a pointaway from the tips 3296 and 3297. This is to avoid putting directpressure on the contact area between the pads from the solenoid shaftand spring which may possibly affect the fluid flow and restrict theflow to some extent.

The transistors 3321 and 3322 may perform current amplification to drivethe solenoids 3251 and 3252, respectively. The transistors 3321 and 3322may be included in the lateral flow assay devices 3200 with a processor505 that cannot supply enough current on the output pins to drive thesolenoids 3251 and 3252. The embodiments with a processor 505 thatprovides sufficient current on its output pins to drive the solenoid3251 and 3252, may not include the transistors 3321 and 3322. Theresistors 3311 and 3312 that are connected between an output pin of themicrocontroller and the base connection of the corresponding transistor3321 and 3322 are for setting the desired current and may be variableresistors that are adjusted at the manufacturing, depending on thecurrent needed to drive the solenoid.

The amount of pressure the conjugate pad 110 may apply on the membrane115 may be controlled by configuring the amount of pressure that thesolenoid shaft 3221 may apply on the spring 3241 and the strength of thespring 3241. The amount of pressure the wicking pad 120 may apply on themembrane 115 may be controlled by configuring the amount of pressurethat the solenoid shaft 3222 may apply on the spring 3242 and thestrength of the spring 3242.

Instead of the solenoids 3351 and 3352, some embodiments may use otheractuation mechanisms such as, for example and without limitation, servomotors to push (and pull) the springs 3241 and 3242. The servo motor mayoperate in a similar way as described above with reference to theelectric motor 530 FIG. 5. For example, the servo motor may include arotor (such as the rotor 570 of FIG. 5) that may rotate and cause arotating shaft (such as the rotating shaft 580 of FIG. 5) to rotate. Therotational movement of the rotating shaft may be converted to linearmovement of a linear moving shaft (such as the linear moving shaft 540of FIG. 5) by a rotational to linear movement converter (such as therotational to linear movement converter 535 of FIG. 5 or the shafts3221/3222 of FIGS. 32-33). The rotational to linear movement convertermay be a set of one or more screws, a wheel and axle, and/or a set ofone or more cams that receive a rotational movement from the rotatingshaft and move the linear moving shaft in a straight line.

The use of servo motors may eliminate the need for the drivertransistors 3321 and 3322 as the servo motors inputs may be directlyconnected to the processor 505 and may not need high currents. The useof servo motors may lead to a more power efficient design. One advantageof using the servo motor is that, unlike the solenoid, the position ofthe spring, and hence the proximity of the overlap area of the conjugatepad 110 and membrane 115, may be accurately controlled, which in turnmay result in having more control in the flow time and flow rate.

The cartridge shown in FIGS. 32-33 is for use with a lateral flow assaydevice that integrates components such as the solenoids, processor,drive transistors, UI (e.g., a keyboard, a display, and/or a touchdisplay), NFC reader, battery, and other switches, connectors, andcomponents.

In another embodiment, all the actuation mechanisms and electronics plusa battery may be integrated inside the cartridge providing a completelystandalone and disposable cartridge. Small servo motors may be used toactuate the springs. Since the cartridge is standalone and for one-timeuse, the battery may be small and does not have to be rechargeable. Theuse of standalone cartridge provides the convenience of not having anexternal device, but it adds to the cost of the cartridge. In anotherembodiment of the standalone cartridge, entirely mechanical timers maybe used to eliminate the need for the battery, servo motor, andprocessor/controller (or other electronic circuits) in the disposablecartridge.

FIGS. 32-33 illustrate an example of a specific arrangement of the pads110, 115, 120 as well as the mechanisms to connection and disconnect thepads. It should be understood that other arrangements may be used forconnecting and disconnecting the pads. For example, the entire systemshown in FIG. 32-33 may designed to be flipped vertically, in which casethe actuators working on the springs may operate from the top. Examplesof this type of arrangements are described below with reference to FIGS.43-46.

As another example, electromagnets may be used instead of the solenoids3251 and/or 3252 and the springs 3241 and 3242 may be made from magneticmaterial. It should be noted that substances that are attracted by amagnet are called magnetic material or magnetic substances. Examples ofthe magnetic material include, for example, and without limitations,iron, cobalt, nickel, etc. Substances that are not attracted by a magnetare called non-magnetic materials. Magnetic materials do not havemagnetic fields around them, but they are attracted by magnetic fields.Magnets, on the other hand, have magnetic fields around them and canattract and repel other magnets. A magnet can attract magnetic materialsbut cannot repel them.

The electromagnet may be located adjacent to the cartridge's housing3230 (e.g., as close as possible to the housing or touching it). Whenthe electromagnet is activated, the magnetic field generated by theelectromagnet may pull the corresponding spring towards theelectromagnet. When the electromagnet is deactivated, the correspondingspring is released. In order not to consume power when the gap betweenthe pads is open, the preferred direction would be for the conjugate pad110 to be on top of the membrane 115 (either moving the membrane of FIG.32 to the floor of the cartridge housing or vertically flipping theentire system in FIG. 32) such that when the electromagnet is activatedand the spring is pulled towards the electromagnet, the conjugate pad110 may come in contact with the membrane 115. In the standalonedisposable version of the cartridge, the electromagnet may be includedinside the cartridge.

In another embodiment of the electromagnet-based implementation, thespring may have a post made from a magnetic material that is permanentlyattached to it and goes through the cartridge housing via a hole on thehousing wall and sits flush with the surface of the housing. Theelectromagnet then interacts with this post. As another example, thespring may have a built-in hook attached to it (e.g., as shown in FIG.9) that is pulled with a shaft that is controlled and moved via a servo,an electromagnet, a solenoid, or linear actuator. The examples describedabove with reference to FIG. 5-7 may be used to move the pads to connectto and disconnect from each other.

As described above with reference to FIGS. 32 and 33, electromagnets maybe used instead of the solenoids 3251 and/or 3252, and the springs 3241and 3242 may be made from magnetic material. In some of theseembodiments, only a portion (e.g., the tip) of the springs 3241 and 3242may be made of magnetic material and the rest of the springs 3241 and3242 may be made of non-magnetic material. In other embodiments, smallpieces of magnetic material may be attached to the tips of the springs3241 and 3242.

FIG. 36 is a front elevation view of one example embodiment of a portionof a lateral flow assay device 3600 that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by a spring mechanism and an electromagnet, accordingto various aspects of the present disclosure. FIG. 37 is a functionalblock diagram illustrating one example embodiment of the lateral flowassay device of FIG. 36, according to various aspects of the presentdisclosure. With reference to the lateral flow assay device 3600 ofFIGS. 36 and 37, the tip of the spring 3241 may be made of magneticmaterial 3661 and the tip of the spring 3242 may be made of magneticmaterial 3662. The rest of the springs 3241 and 3242 may be made ofnon-magnetic material. Alternatively, a piece of magnetic material 3661may be attached (e.g., by glue or other appropriate material) to the tipof the spring 3241 and a piece of magnetic material 3662 may be attachedto the tip of the spring 3242.

With further reference to FIG. 36, the lateral flow assay device 3600may include the electromagnets 3648 and 3649 instead of the solenoids3251-3252 and the solenoid shafts 3221-3222 of FIG. 32. Other componentsof FIG. 36 may be similar to the corresponding components of FIG. 32,which were described above. The electromagnets 3648-3649 may be locatedadjacent to the cartridge's housing 3230 (e.g., as close as possible tothe housing or touching it) without a need to make a hole in the housing(as was needed for the solenoid shafts 3221-3222 of FIG. 32).

Similar to the lateral flow assay device 3200 of FIGS. 32 and 33, in thelateral flow assay device 3600, the flow rate for the membrane pad 115and the flow time (which is the time it takes for the solution to travelfrom one end of the membrane to the other) may be controlled by on-offcycling (pulsing) of the mechanism that brings the conjugate pad 110 andthe membrane pad 115 together. The flow time may be controlled with thetime that the conjugate 110 and the membrane 115 pads are connected (Tc)and the time that the pads are disconnected (Td). The value of theseparameters and the number of times the pads are connected anddisconnected may be determined via an algorithm that uses calibrationtables or calibration curves as described above with reference to FIGS.34 and 35.

If the lateral flow assay device cartridge also includes a flow controlmechanism between the wicking pad and the membrane pad (e.g., as shownin FIGS. 36 and 37), the flow control mechanism between the wicking padand the membrane pad may also have its Tc and Td parameters that mayeither use the same values as the Tc and Td for the mechanism betweenthe conjugate pad and the membrane or it may use its own independent Tcand Td values, as described above.

As shown in FIGS. 36 and 37, the electromagnet 3648 may initially (e.g.,before the start of a test) be deactivated and a gap 3291 may bemaintained between the conjugate pad 110 and the membrane 115.Similarly, a gap 3292 may initially be maintained between the membrane115 and the wicking pad 120 in some embodiments. The gaps 3291 and 3292may be substantially filled by air. The conjugate pad 110 may be heldaway from the membrane 115 by the spring 3241 (and by the weight of themagnetic material 3661) that is attached to the clear backing 3211 ofthe conjugation pad 110. When the electromagnet 3648 is activated, themagnetic field generated by the electromagnet 3648 may pull the magneticmaterial 3661 and the spring 3241 towards the electromagnet 3648resulting in closing the gap 3291 between the conjugate pad 110 and themembrane 115 and causing the conjugate pad 110 to touch the membrane115.

For the embodiments that include a wicking pad (such as the embodimentof FIGS. 36-37), when the electromagnet 3649 is deactivated, the wickingpad 120 may be held away from the membrane 115 by the spring 3242 (andby the weight of the magnetic material 3662) that is attached to theclear backing 3213 of the wicking pad 120 to maintain the gap 3292. Whenthe electromagnet 3649 is activated, the magnetic field generated by theelectromagnet 3649 may pull the magnetic material 3662 and the spring3242 towards the electromagnet 3649 resulting in the gap 3292 betweenthe wicking pad 120 and the membrane 115 to be removed and the wickingpad 120 and the membrane 115 to make contact.

With further reference to FIGS. 36 and 37, the activation anddeactivation of the electromagnets 3648 and 3649 may be controlled inorder to control the flow the fluid material from the conjugate pad 110to the membrane 115 and from the membrane 115 to the wicking pad 120,respectively. Once the specified conjugation time is lapsed (e.g.,specified by the NFC chip 590, received from the UI of the lateral flowassay device, received from an external device, etc.), the electromagnet3648 may be activated by a command from the processor/controller 505(FIG. 37), which may cause the electromagnet 3648 to pull the magneticmaterial 3661 and the spring 3241 such that the conjugate pad 110 tomake contact with the membrane 115 to allow the flow of the fluidmaterial from the conjugate pad 110 to the membrane 115. Theelectromagnet 3648 may be deactivated by a command from theprocessor/controller 505, which may cause the magnetic material 3661 andthe spring 3241 to be released, resulting in the gap 3291 to bemaintained between the conjugate pad 110 and the membrane 115. Theelectromagnet 3648 may include an electromagnetically inductive coil3691 that is wrapped around a metallic core (or ferrite core) 3651. Thedirection of the magnetic field of the coil 3691 may change by thedirection of the current through the coil 3691. Furthermore, when theelectric current is turned off, the coil 3691 may no longer generate amagnetic field.

Similarly, when the electromagnet 3649 is activated by a command fromthe processor/controller 505 (FIG. 37), the electromagnet 3649 may pullthe magnetic material 3662 and the spring 3242 which may cause thewicking pad 120 to make contact with the membrane 115 to allow the flowof the fluid material from the membrane 115 to the wicking pad 120. Theelectromagnet 3649 may be deactivated by a command from theprocessor/controller 505 that causes the magnetic material 3662 and thespring 3242 to be released, resulting in the gap 3292 to be maintainedbetween the conjugate pad 110 and the membrane 115. The electromagnet3649 may include an electromagnetically inductive coil 3692 that iswrapped around a metallic core (or ferrite core) 3652. The direction ofthe magnetic field of the coil 3692 may change by the direction of thecurrent through the coil 3692. Furthermore, when the electric current isturned off, the coil 3692 no longer generates a magnetic field.

The transistors 3321 and 3322 may perform current amplification to drivethe electromagnets 3648 and 3649, respectively. The transistors 3321 and3322 may be included in the lateral flow assay devices 3600 with aprocessor 505 that cannot supply enough current on the output pins todrive the electromagnets 3648 and 3649. The embodiments with a processor505 that provides sufficient current on its output pins to drive theelectromagnets 3648 and 3649, may not include the transistors 3321 and3322. The resistors 3311 and 3312 that are connected between an outputpin of the processor/controller 505 and the base connection of thecorresponding transistor 3321 and 3322 are for setting the desiredcurrent and may be variable resistors that are adjusted at themanufacturing, depending on the current needed to drive the solenoid.

The amount of pressure the conjugate pad 110 may apply on the membrane115 may be controlled by configuring the strength of the magnetic fieldthat the electromagnet 3648 may generate, the strength of the magneticmaterial 3661, and the strength of the spring 3241. The amount ofpressure the wicking pad 120 may apply on the membrane 115 may becontrolled by configuring the strength of the magnetic field that theelectromagnet 3649 may generate, the strength of the magnetic material3662, and the strength of the spring 3242.

Some embodiments may use a piezoelectric actuator instead of thesolenoids 3251-3252 of FIGS. 32-33 or the electromagnets 3648-3649 ofFIGS. 36-37 to control the gaps 3291-3292. A piezoelectric actuatorconverts an electrical signal into a controlled displacement, referredto as stroke. A piezoelectric stack actuator is made by stackingpiezoelectric ceramic discs and metal electrode foils. Applying avoltage to the piezoelectric stack, may result in a controlleddisplacement of the stack. If the displacement is prevented, a force,referred to as blocking force, may develop.

A piezoelectric stack, depending on the type, may require a voltage ofbetween 100 volts to 1000 volts to operate. The precise displacementcontrol of the piezoelectric stack actuators may be used in some of thepresent embodiments to move a shaft to control the gap between theconjugate pad and membrane and to move another shaft to control the gapbetween the wicking pad and the membrane.

FIG. 38 is a front elevation view of one example embodiment of a portionof a lateral flow assay device 3800 that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by a piezoelectric actuator, according to variousaspects of the present disclosure. With reference to FIG. 38, thelateral flow assay device 3800 may include the piezoelectric actuatorstack 3831 to control the gap 3291 between the conjugate pad 110 and themembrane 115.

The piezoelectric actuator, in the example of FIG. 38 is a piezoelectricstack actuator 3831 that may be made of several individual piezoelectricactuators 3830 that are factory made to be connected to each other.Other embodiments may use other types of piezoelectric actuators. Thepiezoelectric actuator stack 3831 may be connected to the shaft 3851.

The piezoelectric stack actuator 3831 may be controlled by theprocessor/controller 505 through the piezoelectric driver 3821. Thepiezoelectric driver 3821 may receive one or more signals from theprocessor/controller 505 and may generate the voltages required foractivating and deactivating the piezoelectric stack actuator 3831.

If the lateral flow assay device cartridge also includes a flow controlmechanism between the wicking pad and the membrane pad (e.g., as shownin FIG. 38), the lateral flow assay device 3800 may include thepiezoelectric actuator stack 3832 to control the gap 3292 between thewicking pad 120 and the membrane 115. The piezoelectric actuator stack3832 may be connected to the shaft 3852. The piezoelectric stackactuator 3832 may be controlled by the processor/controller 505 throughthe piezoelectric driver 3822. The piezoelectric driver 3822 may receiveone or more signals from the processor/controller 505 and may generatethe voltages required for activating and deactivating the piezoelectricstack actuator 3832. Other components of the lateral flow assay deviceof FIG. 38 may be similar to the corresponding components of the lateralflow assay device 3200 of FIGS. 32-33.

FIG. 38 as shown, includes two operational steps 3801 and 3802. As shownin step 3801, a gap 3291 may initially (e.g., at the start of a test) bemaintained between the conjugate pad 110 and the membrane 115 by thespring 3241. A gap 3292 may also initially be maintained between themembrane 115 and the wicking pad by the spring 3242. The gaps 3291 and3292 may be substantially filled by air.

The processor/controller 505, in some embodiments, may send one or moresignals prior to, or at the start of a test, to the piezoelectric driver3821 to deactivate the piezoelectric stack actuator 3831. For example,the piezoelectric driver 3821 may turn off the voltage to thepiezoelectric stack actuator 3831. As shown, the length of thepiezoelectric stack actuator 3831 in step 3801 is d1 and the shaft 3851is not in contact with the spring 3241.

The processor/controller 505, in some embodiments, may also send one ormore signals to the piezoelectric driver 3822 to deactivate thepiezoelectric stack actuator 3832. For example, the piezoelectric driver3822 may turn off the voltage to the piezoelectric stack actuator 3832.As shown, the shaft 3852 is not in contact with the spring 3242.

Once the specified conjugation time is lapsed (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.), the processor/controller 505may send one or more signals, in step 3802, to the piezoelectric driver3821 to activate the piezoelectric stack actuator 3831. Thepiezoelectric driver 3821 may turn on the voltage to the piezoelectricstack actuator 3831.

As shown in step 3802, the length of the piezoelectric stack actuator3831 may expand to d2, generating a stroke of d2−d1. Assuming that thepiezoelectric stack actuator 3831 may equally expand in two oppositedirections, the edge 3880, which is closer to the housing 3230 may moveat a distance of (d2−d1)/2 towards the housing 3230, causing the shaft3851 to move by the same distance of (d2−d1)/2. The lateral flow assaydevice 3800 may be configured such that the movement of the shaft 3851by the distance (d2−d1)/2 may cause the gap 3291 to be removed and theconjugate pad 110 may come in contact with the membrane 115. Once theconjugate pad 110 and the membrane 115 come in full contact, any furtherdisplacement of the piezoelectric stack actuator 3831 may be preventedand may be automatically converted to a blocking force.

The piezoelectric stack actuator 3831 may be repeatedly activated anddeactivated to push the shaft 3851 against the spring 3241 to bring theconjugate pad 110 and the membrane 115 in touch with each other,followed by pulling the shaft 3851 away from the spring 3241 to causethe spring 3241 to separate the conjugate pad 110 from the membrane 115.Repeatedly connecting and disconnecting the conjugate pad 110 and themembrane 115 may be used to control the flow of fluid material from theconjugate pad 110 into the membrane 115, as described above withreference to FIGS. 32-33. The piezoelectric stack actuator 3832 may besimilarly controlled to open and close the gap 3292 between the wickingpad 120 and the membrane 115.

Some embodiments do not use springs in order to open and close the gapsbetween the conjugate pad and the membrane or between the wicking padand membrane. Some of these embodiments may connect a magnet to thebacking of the conjugate pad and/or to the backing of the wicking pad.FIG. 39 is a front elevation view of one example embodiment of a portionof a lateral flow assay device 3900 that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by magnets and electromagnets, according to variousaspects of the present disclosure. FIG. 40 is a functional block diagramillustrating one example embodiment of the lateral flow assay device ofFIG. 39, according to various aspects of the present disclosure.

With reference to FIGS. 39 and 40, the conjugate pad 110 may beconnected to the backing 3211 and the wicking pad 120 may be connectedto the backing 3213. Unlike the lateral flow assay devices of FIGS.32-33 and 36-38, the lateral flow assay device 3900 of FIGS. 39 and 40do not include the springs 3241 and 3242 to pull down the conjugate pad110 and the wicking pad 120, respectively.

The lateral flow assay device 3900 may include a magnet 3971 connectedto the backing 3211 and/or a magnet 3972 connected to the backing 3213.The electromagnets 3648-3649, the coils 3691-36392, and the cores3651-3652, may be similar to the corresponding components of FIG. 37.

Similar to the lateral flow assay device 3200 of FIGS. 32 and 33, in thelateral flow assay device 3900, the flow rate for the membrane pad 115and the flow time (which is the time it takes for the solution to travelfrom one end of the membrane to the other) may be controlled by on-offcycling (pulsing) of the mechanism that brings the conjugate pad and themembrane pad together. The flow time may be controlled with the timethat the conjugate 110 and the membrane 115 pads are connected (Tc) andthe time that the pads are disconnected (Td). The value of theseparameters and the number of times the pads are connected anddisconnected may be determined via an algorithm that uses calibrationtables or calibration curves as described above with reference to FIGS.34 and 35.

If the lateral flow assay device cartridge also includes a flow controlmechanism between the wicking pad and the membrane pad (e.g., as shownin FIGS. 39 and 40), the flow control mechanism between the wicking padand the membrane pad may also have its Tc and Td parameters that mayeither use the same values as the Tc and Td for the mechanism betweenthe conjugate pad and the membrane or it may use its own independent Tcand Td values, as described above.

The activation and deactivation of the electromagnets 3648 and 3649 maybe controlled in order to control the flow of the fluid material fromthe conjugate pad 110 to the membrane 115 and from the membrane 115 tothe wicking pad 120, respectively. Initially (e.g., before the start ofa test), the direction of current in the wire 3360 (FIG. 40) may be setby the processor/controller 505 such that the electromagnet 3648 maypull on the magnet 3971 to maintain the gap 3291 between the conjugatepad 110 and the membrane 115.

Once the specified conjugation time is lapsed (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.), the processor/controller 505may change the direction of current in the wire 3360, such that theelectromagnet 3648 may repel the magnet 3971 to make the conjugate pad110 contact the membrane 115 to allow the flow of the fluid materialfrom the conjugate pad 110 to the membrane 115.

Similarly, the direction of current in the wire 4061 (FIG. 40) may beset by the processor/controller 505 such that the electromagnet 3649 maypull on the magnet 3972 to maintain the gap 3292 between the wicking pad120 and the membrane 115. In order to close the gap 3292, theprocessor/controller 505 may change the direction of current in the wire4061, such that the electromagnet 3649 may repel the magnet 3972 to makethe wicking pad 120 contact the membrane 115 to allow the flow of thefluid material from the membrane 115 to the wicking pad 120.

The amount of pressure the conjugate pad 110 may apply on the membrane115 may be controlled by configuring the strength of the magnetic fieldthat the electromagnet 3648 may generate and the strength of the magnet3971. The amount of pressure the wicking pad 120 may apply on themembrane 115 may be controlled by configuring the strength of themagnetic field that the electromagnet 3649 may generates and thestrength of the magnet 3972.

In alternative embodiments, the lateral flow assay device may beconfigured such that the weight of the magnets 3971 and 3972 may pulldown the conjugate pad under the force of gravity to maintain the gaps3291 and 3292, respectively. In these embodiments, the polarities of theelectromagnet 3648 and the magnet 3971 may be configured such thatprocessor/controller may activate the electromagnet 3648 to repel themagnet 3971 in order to close the gap 3291 and bring the conjugate pad110 in contact with the membrane 115. Similarly, the polarities of theelectromagnet 3649 and the magnet 3972 may be configured such thatprocessor/controller may activate the electromagnet 3649 to repel themagnet 3972 in order to close the gap 3292 and bring the wicking pad 120in contact with the membrane 115.

FIG. 41 is a front elevation view of one example embodiment of a portionof a lateral flow assay device 4100 that that controls the gap betweenthe conjugate pad and the membrane and/or the gap between the wickingpad and the membrane by magnets and electromagnets that are positionedover the lateral flow assay device's housing, according to variousaspects of the present disclosure. FIG. 42 is a functional block diagramillustrating one example embodiment of the lateral flow assay device ofFIG. 41, according to various aspects of the present disclosure.

With reference to FIGS. 41-42, the electromagnets 3648 and 3649 arepositioned over the housing 3230. Other components of FIGS. 41-42 aresimilar to the corresponding components of FIGS. 39-40. With furtherreference to FIG. 41-42, initially (e.g., before the start of a test),the direction of current in the wire 3360 (FIG. 42) may be set by theprocessor/controller 505 such that the electromagnet 3648 may repel(i.e., push on) the magnet 3971 to maintain the gap 3291 between theconjugate pad 110 and the membrane 115.

Once the specified conjugation time is lapsed (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.), the processor/controller 505may change the direction of current in the wire 3360, such that theelectromagnet 3648 may attract the magnet 3971 to make the conjugate pad110 contact the membrane 115 to allow the flow of the fluid materialfrom the conjugate pad 110 to the membrane 115.

Similarly, the direction of current in the wire 4061 (FIG. 42) may beset by the processor/controller 505 such that the electromagnet 3649 mayrepel the magnet 3972 to maintain the gap 3292 between the wicking pad120 and the membrane 115. In order to close the gap 3292, theprocessor/controller 505 may change the direction of current in the wire4061, such that the electromagnet 3649 may attract the magnet 3972 tomake the wicking pad 120 contact the membrane 115 to allow the flow ofthe fluid material from the membrane 115 to the wicking pad 120.

In alternative embodiments, the lateral flow assay device 4100 may beconfigured such that the weight of the magnets 3971 and 3972 may pulldown the conjugate pad under the force of gravity to maintain the gaps3291 and 3292, respectively. In these embodiments, the polarities of theelectromagnet 3648 and the magnet 3971 may be configured such thatprocessor/controller may activate the electromagnet 3648 to attract themagnet 3971 in order to close the gap 3291 and bring the conjugate pad110 in contact with the membrane 115. Similarly, the polarities of theelectromagnet 3649 and the magnet 3972 may be configured such thatprocessor/controller may activate the electromagnet 3649 to attract themagnet 3972 in order to close the gap 3292 and bring the wicking pad 120in contact with the membrane 115.

The amount of pressure the conjugate pad 110 may apply on the membrane115 may be controlled by configuring the strength of the magnetic fieldthat the electromagnet 3648 may generate and the strength of the magnet3971. The amount of pressure the wicking pad 120 may apply on themembrane 115 may be controlled by configuring the strength of themagnetic field that the electromagnet 3649 may generates and thestrength of the magnet 3972.

In all embodiments of FIGS. 32-33 and 36-42, the role of the conjugatepad and the membrane in controlling the gap between the two may beswitched. The spring mechanisms, the magnets, or the combination of bothmay be placed on the membrane instead of the conjugate pad. In theseembodiments, the conjugate pad is stationary and the membrane may moveup and down to control the opening and closing of the gap between thetwo.

Similarly, In all embodiments of FIGS. 32-33 and 36-42, the role of thewicking pad and the membrane in controlling the gap between the two maybe switched. The spring mechanisms, the magnets, or the combination ofboth may be placed on the membrane instead of the wicking pad. In thiscase, the wicking pad is stationary and the membrane may move up anddown to control the opening and closing of the gap between the two.

Alternatively, a mix of both approaches may be used where one side mayhave a stationary conjugate pad and a moving membrane while the otherside may have a moving wicking pad and a stationary membrane. And yet inanother alternative, a mix of both approaches may be used where one sidemay have a moving conjugate pad and a stationary membrane while theother side may have a stationary wicking pad and a moving membrane.

FIG. 43 is a front elevation view of one example embodiment of a portionof a lateral flow assay device 4300 that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by moving a portion of the membrane with a springmechanism, according to various aspects of the present disclosure. Withreference to FIG. 43, the lateral flow assay device 4300 is configuredsuch that the conjugate pad 110 and the wicking pad 120 are positionedon the floor (or the bottom side) of the cartridge housing and themembrane 155 is positioned on the side opposite to the floor, facingtowards the conjugate pad 110 and the wicking pad 120. As shown, themembrane 115 may be held in place by several tabs (or poles) 4390. Thetabs 4390 may be narrow poles configured to hold the membrane 115 inplace with minimal contact with the surface of the membrane in order notto impede the flow of the liquid over the membrane 115. The springs 4341and 4342 may be secured to the housing 3205 by the pins or screws4351-4352.

With further reference to FIG. 43, the solenoids 3251 and 3252 mayinclude the solenoid shafts 3221 and 3222, respectively. The solenoids3251 and 3252 may be positioned on the top of the housing 3230. Othercomponents of the lateral flow assay device 4300 may provide similarfunctionalities as the corresponding components of FIG. 32.

FIG. 43 as shown, includes two operational steps 4301 and 4302. As shownin step 4301, a gap 4391 may initially (e.g., at the start of a test) bemaintained between the conjugate pad 110 and the membrane 115 by thespring 4341. The spring 4341 may be configured such that the spring 4341holds a portion of the membrane 115 and the clear backing 3212 downtowards the conjugate pad 110 without the membrane 115 and the conjugatepad 110 touching each other. As shown in step 4301, a gap 4391 ismaintained between the conjugate pad 110 and the membrane 115.

A gap 4392 may also initially be maintained between the membrane 115 andthe wicking pad by the spring 4342. The spring 4342 may be configuredsuch that the spring 4342 holds a portion of the membrane 115 and theclear backing 3212 down towards the wicking pad 120 without the membrane115 and the wicking pad 120 touching each other. As shown in step 4301,a gap 4392 is maintained between the wicking pad 120 and the membrane115. The gaps 4391 and 4392 may be substantially filled by air.

The lateral flow assay device 4300 may be configured such that in step4301 the solenoid shaft 3221 of the solenoid 3251 is kept away from thespring 4311. For example, the power to the solenoid 3251 may be turnedoff and/or the lateral flow assay device's processor/controller (notshown for simplicity) may send one or more signals prior to, or at thestart of a test, to the solenoid 3251 to keep the shaft 3221 away fromthe spring 4341.

The lateral flow assay device 4300 may be configured such that in step4301 the solenoid shaft 3222 of the solenoid 3252 is kept away from thespring 4312. For example, the power to the solenoid 3252 may be turnedoff and/or the lateral flow assay device's processor/controller may sendone or more signals prior to, or at the start of a test, to the solenoid3252 to keep the shaft 3222 away from the spring 4342.

Once the specified conjugation time is lapsed (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.), the processor/controller maysend one or more signals, in step 4302, to the solenoid 3251 to move theshaft 3221 to push the spring 4341 towards the conjugate pad 110. Asshown in step 4302, the solenoid shaft 3221 may cause the gap 4391 to beremoved and the membrane 115 may come in contact with the conjugate pad110.

The solenoid shaft 3221 may be repeatedly moved down to push against thespring 4341 to bring the membrane 115 and the conjugate pad 110 in touchwith each other, followed by pulling the shaft 3221 away from the spring4341 to cause the spring 4341 to separate the membrane 115 from theconjugate pad 110. Repeatedly connecting and disconnecting the membrane115 and the conjugate pad 110 may be used to control the flow of fluidmaterial from the conjugate pad 110 into the membrane 115, as describedabove with reference to FIGS. 32-33. A similar process may be used tocontrol the gap 4392 between the membrane 115 and the wicking pad 120 byrepeatedly moving the shaft 3222 up and down.

The amount of pressure the membrane 115 may apply on the conjugate pad110 may be controlled by configuring the amount of pressure that theshaft 3221 may apply on the spring 4341 and the strength of the spring4341. The amount of pressure the membrane 115 may apply on the wickingpad 120 may be controlled by configuring the amount of pressure that theshaft 3222 may apply on the spring 4342 and the strength of the spring4342.

FIG. 44 is a front elevation view of one example embodiment of a portionof a lateral flow assay device 4400 that controls the gap between theconjugate pad and the membrane and/or the gap between the wicking padand the membrane by a piezoelectric actuator that moves a portion of themembrane, according to various aspects of the present disclosure.

With reference to FIG. 44, the lateral flow assay device 4400 isconfigured such that the conjugate pad 110 and the wicking pad 120 arepositioned on the floor (or the bottom side) of the cartridge housingand the membrane 155 is positioned on the opposite side of the floorfacing towards the conjugate pad 110 and the wicking pad 120. As shown,the membrane 115 may be held in place by several tabs (or poles) 4390,which may be similar to the tabs 4390 of FIG. 43.

With reference to FIG. 44, the lateral flow assay device 4400 mayinclude the piezoelectric actuator stack 3831 to control the gap 4391between the conjugate pad 110 and the membrane 115. The piezoelectricactuator may be similar to the piezoelectric stack actuator 3831 of FIG.38 and may be controlled by the processor/controller 505 through thepiezoelectric driver 3821, as described above with reference to FIG. 38.

If the lateral flow assay device cartridge also includes a flow controlmechanism between the wicking pad 120 and the membrane pad 115 (e.g., asshown in FIG. 44), the lateral flow assay device 4400 may include thepiezoelectric actuator stack 3832 to control the gap 4392 between thewicking pad 120 and the membrane 115. The piezoelectric actuator stack3832 may be connected to the shaft 3852. The piezoelectric stackactuator 3832 may be controlled by the processor/controller 505 throughthe piezoelectric driver 3822, as described above with reference to FIG.38. The piezoelectric stack actuators 4332-3832 may be positioned on thetop of the housing 3230. Other components of the lateral flow assaydevice 4400 of FIG. 44 may be similar to the corresponding components ofthe lateral flow assay device of FIGS. 32-33 and 38.

FIG. 44, as shown, includes two operational steps 4401 and 4402. Asshown in step 4401, a gap 4391 may initially (e.g., at the start of atest) be maintained between the conjugate pad 110 and the membrane 115by the spring 4341. The spring 4341 may be configured such that thespring 4341 holds a portion of the membrane 115 and the clear backing3212 down towards the conjugate pad 110 without the membrane 115 and theconjugate pad 110 touching each other. As shown in step 4401, a gap 4391is maintained between the conjugate pad 110 and the membrane 115.

A gap 4392 may also initially be maintained between the membrane 115 andthe wicking pad by the spring 4342. The spring 4342 may be configuredsuch that the spring 4342 holds a portion of the membrane 115 and theclear backing 3212 down towards the wicking pad 120 without the membrane115 and the wicking pad 120 touching each other. As shown in step 4401,a gap 4392 is maintained between the wicking pad 120 and the membrane115. The gaps 4391 and 4392 may be substantially filled by air.

Once the specified conjugation time is lapsed (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.), the processor/controller 505may send one or more signals, in step 4402, to the piezoelectric driver3821 to activate the piezoelectric stack actuator 3831. Thepiezoelectric driver 3821 may turn on the voltage to the piezoelectricstack actuator 3831.

As shown in step 4402, the length of the piezoelectric stack actuator3831 may expand and may move the shaft 3851 to push the spring 4341down, as described above with reference to step 3802 of FIG. 38. Thelateral flow assay device 4400 may be configured such that the movementof the shaft 3851 may cause the gap 4391 to be removed and the membrane115 may come in contact with the conjugate pad 110. Once the membrane115 and the conjugate pad 110 come to full contact, any furtherdisplacement of the piezoelectric stack actuator 3831 may be preventedand may be automatically converted to a blocking force.

The piezoelectric stack actuator 3831 may be repeatedly activated anddeactivated to push the shaft 3851 against the spring 4341 to bring themembrane 115 and the conjugate pad 110 in touch with each other,followed by pulling the shaft 3851 away from the spring 4341 to causethe spring 4341 to separate the membrane 115 from the conjugate pad 110.Repeatedly connecting and disconnecting the membrane 115 and theconjugate pad 110 may be used to control the flow of fluid material fromthe conjugate pad 110 into the membrane 115, as described above withreference to FIGS. 32-33. A similar process may be used to control thegap 4392 between the membrane 115 and the wicking pad 120 by repeatedlyactivating and deactivating the piezoelectric actuator stack 3832.

The amount of pressure the membrane 115 may apply on the conjugate pad110 may be controlled by configuring the stroke and the blocking forceof the piezoelectric stack 3831, and by configuring the strength of thespring 4341. The amount of pressure the membrane 115 may apply on thewicking pad 120 may be controlled by configuring the stroke and theblocking force of the piezoelectric stack 3832, and by configuring thestrength of the spring 4342.

FIG. 45 is a front elevation view of one example embodiment of a portionof a lateral flow assay device 4500 that that controls the gap betweenthe conjugate pad and the membrane and/or the gap between the wickingpad and the membrane by a spring mechanism and an electromagnet thatmoves a portion of the membrane, according to various aspects of thepresent disclosure. With reference to FIG. 45, the lateral flow assaydevice 4500 is configured such that the conjugate pad 110 and thewicking pad 120 are positioned on the floor (or the bottom side) of thecartridge housing and the membrane 155 is positioned on the oppositeside of the floor facing towards the conjugate pad 110 and the wickingpad 120. As shown, the membrane 115 may be held in place by several tabs(or poles) 4390, which may be similar to the tabs 4390 of FIG. 43.

With reference to the lateral flow assay device 4500 of FIG. 45, the tipof the spring 4341 may be made of magnetic material 3661 and the tip ofthe spring 4342 may be made of magnetic material 3662. The rest of thesprings 4341 and 4342 may be made of non-magnetic material.Alternatively, a piece of magnetic material 3661 may be attached (e.g.,by glue or other appropriate material) to the tip of the spring 4341 anda piece of magnetic material 3662 may be attached to the tip of thespring 4342.

With further reference to FIG. 45, the lateral flow assay device 4500may include the electromagnets 3648 and 3649, which may be similar tothe electromagnets 3648 and 3649 of FIG. 36. Other components of FIG. 45may be similar to the corresponding components of FIGS. 36 and 43, whichwere described above.

FIG. 45 as shown, includes two operational steps 4501 and 4502. As shownin step 4501, a gap 4391 may initially (e.g., at the start of a test) bemaintained between the conjugate pad 110 and the membrane 115 by thespring 4341. The spring 4341 may be configured such that the spring 4341holds a portion of the membrane 115 and the clear backing 3212 downtowards the conjugate pad 110 without the membrane 115 and the conjugatepad 110 touching each other. As shown in step 4501, a gap 4391 ismaintained between the conjugate pad 110 and the membrane 115.

A gap 4392 may also initially be maintained between the membrane 115 andthe wicking pad by the spring 4342. The spring 4342 may be configuredsuch that the spring 4342 holds a portion of the membrane 115 and theclear backing 3212 down towards the wicking pad 120 without the membrane115 and the wicking pad 120 touching each other. As shown in step 4501,a gap 4392 is maintained between the wicking pad 120 and the membrane115. The gaps 4391 and 4392 may be substantially filled by air.

The lateral flow assay device 4500, in some embodiments, may beconfigured such that in step 4501 the power to the electromagnet 3648 isturned off and the spring 4341 may be configured such that the springpushes a portion of the membrane 115 and a portion of the clear backing3212 such that the gap 4391 is still maintained between the membrane 115and the conjugate pad 110. In other embodiments, the direction ofcurrent to the electromagnet 3648, the strength of the magnetic fieldgenerated by the electromagnet 3698, and the strength of the spring 4341may be configured such that, in step 4501, the gap 4391 is stillmaintained between the membrane 115 and the conjugate pad 110.

In the embodiments that control a gap between the wicking pad and themembrane (e.g., the embodiment shown in FIG. 45), the lateral flow assaydevice 4500 may be configured such that, in step 4501, the power to theelectromagnet 3649 is turned off and the spring 4342 may be configuredsuch that the spring pushes a portion of the membrane 115 and a portionof the clear backing 3212 such that the gap 4392 is still maintainedbetween the membrane 115 and the wicking pad 120. In other embodiments,the direction of current to the electromagnet 3649, the strength of themagnetic field generated by the electromagnet 3699, and the strength ofthe spring 4342 may be configured such that, in step 4501, the gap 4392is still maintained between the membrane 115 and the wicking pad 120.

Once the specified conjugation time is lapsed (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.), the processor/controller (notshown) of the lateral flow device 4500 may send one or more signals, instep 4502, to the electromagnet 3648 to push the spring 4341 towards theconjugate pad 110.

As shown in step 4502, the gap 4391 may be removed and the membrane 115may come in contact with the conjugate pad 110. The electromagnet 3648may be repeatedly turned on and off (or the direction of the current inthe electromagnet 3648 may repeatedly be changed) to push the spring4341 to bring the membrane 115 and the conjugate pad 110 in touch witheach other, followed by releasing the spring 4341 (or by pulling spring4341 towards the electromagnet) to cause the spring 4341 to separate themembrane 115 from the conjugate pad 110. Repeatedly connecting anddisconnecting the membrane 115 and the conjugate pad 110 may be used tocontrol the flow of fluid material from the conjugate pad 110 into themembrane 115, as described above with reference to FIGS. 32-33. Asimilar process may be used to control the gap 4392 between the membrane115 and the wicking pad 120 by repeatedly turning electromagnet 3649 onand off or by repeatedly changing the direction of the current in theelectromagnet 3649.

The amount of pressure the membrane 115 may apply on the conjugate pad110 may be controlled by configuring the strength of the magnetic fieldthat the electromagnet 3648 may generate, the strength of the magneticmaterial 3661, and the strength of the spring 4341. The amount ofpressure the membrane 115 may apply on the wicking pad 120 may becontrolled by configuring the strength of the magnetic field that theelectromagnet 3649 may generate, the strength of the magnetic material3662, and the strength of the spring 4342.

FIG. 46 is a front elevation view of one example embodiment of a portionof a lateral flow assay device 4600 that controls the gap between theconjugate pad and the membrane and/or between the wicking pad and themembrane by a magnet and an electromagnet that moves a portion of themembrane, according to various aspects of the present disclosure. Withreference to FIG. 46, the lateral flow assay device 4600 may have asimilar configuration as the lateral flow assay device 4500 of FIG. 45,except that the lateral flow assay device 4600 does not include thesprings 4341-4342 and instead has the magnets 3971 and 3972 that areconnected to the two sides of the clear backing 3212.

FIG. 46 as shown, includes two operational steps 4601 and 4602. As shownin step 4601, a gap 4391 may initially (e.g., at the start of a test) bemaintained between the conjugate pad 110 and the membrane 115 by thespring 4341. The lateral flow assay device 4600, in some embodiments,may be configured such that, in step 4601, the power to theelectromagnet 3648 is turned off, and the spring 4341 may be configuredsuch that the spring pushes a portion of the membrane 115 and a portionof the clear backing 3212 while the gap 4391 is still maintained betweenthe membrane 115 and the conjugate pad 110. In other embodiments, thedirection of current to the electromagnet 3648, the strength of themagnetic field generated by the electromagnet 3698, and the strength ofthe spring 4341 may be configured such that, in step 4601, the gap 4391is still maintained between the membrane 115 and the conjugate pad 110.

In the embodiments that control a gap between the wicking pad 120 andthe membrane 115 (e.g., the embodiment shown in FIG. 46), the lateralflow assay device 4600 may be configured such that in step 4601 thepower to the electromagnet 3649 is turned off and the spring 4342 may beconfigured such that the spring pushes a portion of the membrane 115 anda portion of the clear backing 3212 while that the gap 4392 is stillmaintained between the membrane 115 and the wicking pad 120. In otherembodiments, the direction of current to the electromagnet 3649, thestrength of the magnetic field generated by the electromagnet 3649, andthe strength of the spring 4342 may be configured such that, in step4601, the gap 4392 is still maintained between the membrane 115 and thewicking pad 120.

Once the specified conjugation time is lapsed (e.g., specified by theNFC chip 590, received from the UI of the lateral flow assay device,received from an external device, etc.), the processor/controller (notshown) of the lateral flow device 4600 may send one or more signals, instep 4602, to the electromagnet 3648 to push the magnet 3971 towards theconjugate pad 110.

As shown in step 4602, the gap 4391 may be removed and the membrane 115may come in contact with the conjugate pad 110. The electromagnet 3648may be repeatedly turned on and off (or the direction of the current inthe electromagnet 3648 may repeatedly be changed) to push the magnet3971 to bring the membrane 115 and the conjugate pad 110 in touch witheach other, followed by pulling magnet 3971 towards the electromagnet toseparate the membrane 115 from the conjugate pad 110. Repeatedlyconnecting and disconnecting the membrane 115 and the conjugate pad 110may be used to control the flow of fluid material from the conjugate pad110 into the membrane 115, as described above with reference to FIGS.32-33. A similar process may be used to control the gap 4392 between themembrane 115 and the wicking pad 120 by repeatedly turning electromagnet3649 on and off or by repeatedly changing the direction of the currentin the electromagnet 3649.

The amount of pressure the membrane 115 may apply on the conjugate pad110 may be controlled by configuring the strength of the magnetic fieldthat the electromagnet 3648 may generate and the strength of the magnet3971. The amount of pressure the membrane 115 may apply on the wickingpad 120 may be controlled by configuring the strength of the magneticfield that the electromagnet 3649 may generate and the strength of themagnet 3972.

As an alternative to the configuration of the conjugate pad 110, themembrane 115, and the wicking pad 120 of FIGS. 43-46, the lateral flowassay in some embodiments may be configured such that the conjugate pad110 and the wicking pad to be on top of the membrane 115, either bymoving the membrane to the floor of the cartridge housing or verticallyflipping the entire system. For example, in such an alternativeconfiguration for FIG. 36, when the electromagnet 3648 is deactivated,the spring 3241 may push down the conjugate pad 110 away from themembrane to maintain the gap 3291. In these alternative embodiments, theelectromagnet 3648 may be placed under the housing 3230, such that, whenthe electromagnet 3648 is activated, the magnetic material 3261 and thespring 3241 are pulled down towards the electromagnet 3248 to make theconjugate pad 110 to come in contact with the membrane 115.

Furthermore, in this configuration, the electromagnet 3649 may be placedunder the housing 3230. When the electromagnet 3649 is deactivated, thespring 3242 may push down the wicking pad 120 away from the membrane tomaintain the gap 3292. When the electromagnet 3649 is activated, themagnetic material 3262 and the spring 3242 are pulled down towards theelectromagnet 3649 to make the wicking pad 120 to come in contact withthe membrane 115.

As another alternative to the embodiments of FIGS. 43-46, a mix of twoapproaches may be used where one side may have a stationary conjugatepad and a moving membrane while the other side may have a moving wickingpad and a stationary membrane. And yet in another alternative, a mix oftwo approaches may be used where one side may have a moving conjugatepad and a stationary membrane while the other side may have a stationarywicking pad and a moving membrane.

With reference to FIGS. 20-31, the exemplary embodiments were describedwith reference to removing the gap between the pads at once. Forexample, FIG. 21 was described by moving down the section 2106 of thelateral flow device's housing to remove the gap 2050. In otherembodiments, the gap 2050 may be repeatedly opened and closed by movingthe section 2106 of the housing up and down in order to repeatedly bringthe conjugate pad 110 and the membrane 115 in touch with each other andthen separate them from each other. Repeatedly connecting anddisconnecting the conjugate pad 110 and the membrane 115 provides thetechnical advantage of controlling the flow of fluid material from theconjugate pad 110 into the membrane 115.

The number of times the moving section 2106 is moved up or down, theduration that the moving section 2106 stays up or down, and the timebetween the moving up and down actions may control the amount of contactbetween the conjugate pad 110 and the membrane 115. The amount ofcontact between the conjugate pad 110 and the membrane 115 may in turnbe used by the processor of the lateral flow assay device to control theflow time (the time would take for the fluid material to travel thelength of the membrane 115, going over the test line 125 and the controlline 135 to reach the wicking pad 120).

With reference to FIG. 28, a similar technique may be used to repeatedlymove the sections 2806, 2807, and/or 2808 up or down to control the timethe fluid material comes in contact with the test line 125, the time thefluid material comes in contact with the control line 130, and/or theflow rate across the flow path of the lateral flow assay device.

With reference to FIG. 23, the pole 2310 was described to moving down toremove the gap 2050. In other embodiments, the gap 2050 may berepeatedly opened and closed by moving the pole 2310 up and down inorder to repeatedly bring the conjugate pad 110 and the membrane 115 intouch with each other and then separate them from each other. Repeatedlyconnecting and disconnecting the conjugate pad 110 and the membrane 115may be used to control the flow of fluid material from the conjugate pad110 into the membrane 115.

With reference to FIG. 29, a similar technique may be used to repeatedlymove the poles 2310, 2911, and/or 2912 up or down, which provides thetechnical advantage of controlling the time the fluid material comes incontact with the test line 125, the time the fluid material comes incontact with the control line 130, and/or the flow rate across the flowpath of the lateral flow assay device.

One advantage of using a servo or a linear actuator for moving the shaftthat pushes the spring 3241 (and/or 3242) is that the position of theshaft 3221 (and/or 3222) may be accurately controlled, which in turnresults in the technical advantage of being able to control theproximity of the overlap area of the conjugate pad 110 and the membrane115 (and/or, similarly, the overlap area of the membrane 115 and thewicking pad 120).

The accurate control over the proximity, which also controls the amountof pressure between the two pads at the overlap area, is anotherindependent parameter in controlling the flow rate and flow time. Forthe embodiments of the lateral flow assays that use this feature, theset of the calibration tables or calibration curves may be generated foreach distinct position of the servo. Without limitations, the distinctpositions of the servo shaft may usually be few in practical cases. If aservo or linear actuator is used on both the conjugate pad side as wellof the wicking pad side of the device, then there may be two sets ofpositions for which the calibration tables or curves need to begenerated. For example, if the distinct positions of the servo arelimited to three positions for each side, there will be nine differentcombination of the two positions resulting in nine different sets ofcalibration tables or curves.

III. Computer System

Some of the above-described features and applications are implemented assoftware processes that are specified as a set of instructions recordedon a computer readable storage medium (also referred to as computerreadable medium). When these instructions are executed by one or moreprocessing unit(s) (e.g., one or more processors, cores of processors,or other processing units), they cause the processing unit(s) to performthe actions indicated in the instructions. Examples of computer readablemedia include, but are not limited to, CD-ROMs, flash drives, RAM chips,hard drives, EPROMs, etc. The computer readable media does not includecarrier waves and electronic signals passing wirelessly or over wiredconnections.

In this specification, the term “software” is meant to include firmwareresiding in read-only memory or applications stored in magnetic storage,which can be read into memory for processing by a processor. Also, insome embodiments, multiple software inventions can be implemented assub-parts of a larger program while remaining distinct softwareinventions. In some embodiments, multiple software inventions can alsobe implemented as separate programs. Finally, any combination ofseparate programs that together implement a software invention describedhere is within the scope of the invention. In some embodiments, thesoftware programs, when installed to operate on one or more electronicsystems, define one or more specific machine implementations thatexecute and perform the operations of the software programs.

FIG. 47 conceptually illustrates an electronic system 4700 with whichsome embodiments of the invention (e.g., the microprocessors, themicrocontrollers, the controller, the client devices described above)are implemented. The electronic system 4700 can be used to execute anyof the control, virtualization, or operating system applicationsdescribed above. The electronic system 4700 may be a computer (e.g.,desktop computer, personal computer, tablet computer, server computer,mainframe, blade computer etc.), phone, PDA, or any other sort ofelectronic device. Such an electronic system includes various types ofcomputer readable media and interfaces for various other types ofcomputer readable media. Electronic system 4700 includes a bus 4705,processing unit(s) 4710, a system memory 4720, a read-only memory (ROM)4730, a permanent storage device 4735, input devices 4740, and outputdevices 4745.

The bus 4705 collectively represents all system, peripheral, and chipsetbuses that communicatively connect the numerous internal devices of theelectronic system 4700. For instance, the bus 4705 communicativelyconnects the processing unit(s) 4710 with the read-only memory 4730, thesystem memory 4720, and the permanent storage device 4735.

From these various memory units, the processing unit(s) 4710 retrieveinstructions to execute and data to process in order to execute theprocesses of the invention. The processing unit(s) may be a singleprocessor or a multi-core processor in different embodiments.

The read-only-memory 4730 stores static data and instructions that areneeded by the processing unit(s) 4710 and other modules of theelectronic system. The permanent storage device 4735, on the other hand,is a read-and-write memory device. This device is a non-volatile memoryunit that stores instructions and data even when the electronic system4700 is off. Some embodiments of the invention use a mass-storage device(such as a magnetic or optical disk and its corresponding disk drive) asthe permanent storage device 4735.

Other embodiments use a removable storage device (such as a floppy disk,flash drive, etc.) as the permanent storage device. Like the permanentstorage device 4735, the system memory 4720 is a read-and-write memorydevice. However, unlike storage device 4735, the system memory is avolatile read-and-write memory, such as random access memory. The systemmemory stores some of the instructions and data that the processor needsat runtime. In some embodiments, the invention's processes are stored inthe system memory 4720, the permanent storage device 4735, and/or theread-only memory 4730. From these various memory units, the processingunit(s) 4710 retrieve instructions to execute and data to process inorder to execute the processes of some embodiments.

The bus 4705 also connects to the input and output devices 4740 and4745. The input devices enable the user to communicate information andselect commands to the electronic system. The input devices 4740 includealphanumeric keyboards and pointing devices (also called “cursor controldevices”). The output devices 4745 display images generated by theelectronic system. The output devices include printers and displaydevices, such as cathode ray tubes (CRT) or liquid crystal displays(LCD). Some embodiments include devices, such as a touchscreen, thatfunction as both input and output devices.

Finally, as shown in FIG. 47, bus 4705 also couples electronic system4700 to a network 4725 through a network adapter (not shown). In thismanner, the computer can be a part of a network of computers (such as alocal area network (“LAN”), a wide area network (“WAN”), an Intranet, ora network of networks, such as the Internet. Any or all components ofelectronic system 4700 may be used in conjunction with the invention.

Some embodiments include electronic components, such as microprocessors,storage, and memory, that store computer program instructions in amachine-readable or computer-readable medium (alternatively referred toas computer-readable storage media, machine-readable media, ormachine-readable storage media). Some examples of such computer-readablemedia include RAM, ROM, read-only compact discs (CD-ROM), recordablecompact discs (CD-R), rewritable compact discs (CD-RW), read-onlydigital versatile discs (e.g., DVD-ROM, dual-layer DVD-ROM), a varietyof recordable/rewritable DVDs (e.g., DVD-RAM, DVD-RW, DVD+RW, etc.),flash memory (e.g., SD cards, mini-SD cards, micro-SD cards, etc.),magnetic and/or solid state hard drives, read-only and recordableBlu-Ray® discs, ultra density optical discs, any other optical ormagnetic media, and floppy disks. The computer-readable media may storea computer program that is executable by at least one processing unitand includes sets of instructions for performing various operations.Examples of computer programs or computer code include machine code,such as is produced by a compiler, and files including higher-level codethat are executed by a computer, an electronic component, or amicroprocessor using an interpreter.

While the above discussion primarily refers to microprocessor ormulti-core processors that execute software, some embodiments areperformed by one or more integrated circuits, such as applicationspecific integrated circuits (ASICs) or field programmable gate arrays(FPGAs). In some embodiments, such integrated circuits executeinstructions that are stored on the circuit itself.

As used in this specification, the terms “computer,” “server,”“processor,” “processing unit,” “controller,” and “memory” all refer toelectronic or other technological devices. These terms exclude people orgroups of people. For the purposes of the specification, the termsdisplay or displaying means displaying on an electronic device. As usedin this specification, the terms “computer readable medium,” “computerreadable media,” and “machine readable medium” are entirely restrictedto tangible, physical objects that store information in a form that isreadable by a computer. These terms exclude any wireless signals, wireddownload signals, and any other ephemeral or transitory signals.

While the invention has been described with reference to numerousspecific details, one of ordinary skill in the art will recognize thatthe invention can be embodied in other specific forms without departingfrom the spirit of the invention. In addition, a number of the figures(including FIGS. 11 and 26) conceptually illustrate processes. Thespecific operations of these processes may not be performed in the exactorder shown and described. The specific operations may not be performedin one continuous series of operations, and different specificoperations may be performed in different embodiments. Furthermore, theprocess could be implemented using several sub-processes, or as part ofa larger macro process.

In a first aspect, a lateral flow assay device, comprises: a conjugatepad configured to receive a quantity of fluid; a membrane comprising atest line for determining whether the fluid comprises a target analyte;and a removable physical barrier, wherein, in a first state of thelateral flow assay device, the removable physical barrier is between theconjugate pad and the membrane and prevents the fluid from flowing fromthe conjugate pad into the membrane, and wherein, in a second state ofthe lateral flow assay device, the removable physical barrier is removedfrom between the conjugate pad and the membrane causing the conjugatepad to be connected to the membrane and allowing the fluid to flow fromthe conjugate pad into the membrane and the test line by capillaryaction.

In an embodiment of the first aspect, the lateral flow assay devicefurther comprises at least a first magnet connected to the removablephysical barrier for pulling out the removable physical barrier frombetween the conjugate pad and the membrane by a second magnet externalto the lateral flow assay device.

In another embodiment of the first aspect, the conjugate pad contains anantibody for binding to the target analyte, wherein the target analyteand the antibody require a first time period to bind, the lateral flowassay device further comprises at least a first magnet connected to theremovable physical barrier; an electromagnet comprising a coil and acore, wherein the core acts as a magnet when a current is passed throughthe coil, wherein the core does not act as a magnet when no current ispassed through the coil, wherein the core is configured to stay at aspecific distance from the first magnet at a beginning of an assay test,and wherein the core is configured to attract the first magnet and pullthe removable physical barrier from between the conjugate pad and themembrane when the core acts as a magnet and the core is at the specificdistance from the first magnet; and a processing unit configured to:disconnect the current from the coil prior to the beginning of the assaytest; and after the first time period from the beginning of the assaytest, connecting the current to the coil to cause the core to act as amagnet and pull the first magnet and the movable physical barrier frombetween the conjugate pad and the membrane.

In another embodiment of the first aspect, the fluid is transported fromthe conjugate pad to the membrane by capillary action, and the firsttime period is greater than a time that takes for the fluid to betransported by capillary action from the sample pad to the conjugate padand from the conjugate pad to the membrane.

In another embodiment of the first aspect, the lateral flow assay devicefurther comprises at least one hole on the removable physical barrierfor pulling out the removable physical barrier from between theconjugate pad and the membrane by at least one hook engaged into the atleast one hole.

In another embodiment of the first aspect, the lateral flow assay devicefurther comprises at least one hole on the removable physical barrier;and at least one string going through the at least one pole for pullingout the removable physical barrier from between the conjugate pad andthe membrane by at least one hook engaged into the at least one string.

In another embodiment of the first aspect, the lateral flow assay devicefurther comprises at least one grove on the removable physical barrierfor pulling out the removable physical barrier from between theconjugate pad and the membrane.

In another embodiment of the first aspect, wherein the removablephysical barrier is a first removable physical barrier, and wherein themembrane is a first membrane, the lateral flow assay device furthercomprises: a second membrane comprising a control line for determiningwhether the lateral flow assay device has successfully analyzed thefluid; and a second removable physical barrier, wherein, in a thirdstate of the lateral flow assay device, the second removable physicalbarrier is between the first and second membranes and preventing thefluid from flowing from the first membrane and the test line into thesecond membrane, and wherein, in a fourth state of the lateral flowassay device, the second removable physical barrier is removed frombetween the first and the second membranes causing the first membrane tobe connected to the second membrane and allowing the fluid to flow fromthe first membrane and the test line into the second membrane and thecontrol line by capillary action.

In another embodiment of the first aspect, the lateral flow assay devicefurther comprises: a wicking pad; and a third removable physicalbarrier, wherein, in a fifth state of the lateral flow assay device, thethird removable physical barrier is between the second membrane and thewicking pad and preventing the fluid from flowing from the secondmembrane and the control line into the wicking pad, and wherein, in asixth state of the lateral flow assay device, the third removablephysical barrier is removed from between the second membrane and thewicking pad causing the second membrane to be connected to the wickingpad and allowing the fluid to flow from the second membrane and thecontrol line into the wicking pad by capillary action.

In another embodiment of the first aspect, the lateral flow assay devicefurther comprises a sample pad fluidically connected to the conjugatepad, wherein the sample is configured to receive said quantity of fluidand transport the fluid to the conjugate pad by capillary action.

In another embodiment of the first aspect, the lateral flow assay devicefurther comprises a housing comprising a housing bed, where a portion ofthe conjugate pad and a portion of the membrane are located on thehousing bed, wherein the housing bed has a permanent gap, wherein insaid first state of the lateral flow assay device, the permanent gap inthe housing bed prevents the fluid from leaking from the conjugate padinto the membrane.

In a second aspect, a lateral flow assay device, comprises: a sample padfor receiving a quantity of fluid; a conjugate pad fluidically connectedto the sample pad, wherein the sample pad is configured to transport thefluid to the conjugate pad by capillary action; and a membranecomprising a test line for determining whether the fluid comprises atarget analyte, wherein, in a first state of the lateral flow assaydevice, the lateral flow assay device is configured with a removable gapbetween the conjugate pad and the membrane, the removable gapsubstantially filled with air and preventing the fluid from flowing fromthe conjugate pad into the membrane, and wherein, in a second state ofthe lateral flow assay device, the removable gap is removed from betweenthe conjugate pad and the membrane causing the conjugate pad to come incontact with the membrane and allowing the fluid to flow from theconjugate pad into the membrane and the test line by capillary action.

In an embodiment of the second aspect, the lateral flow assay devicefurther comprises: a housing covering at least a portion of theconjugate pad and the membrane, wherein the housing comprises a movablesection comprising a side attached to at least a portion of theconjugate pad, wherein, in the first state of the lateral flow assaydevice, the movable section creates the removable gap by keeping theconjugate pad and the membrane separate, and wherein, in the secondstate of the lateral flow assay device, the movable section pushes theconjugate pad towards the membrane causing the conjugate pad and themembrane to come in contact with each other.

In another embodiment of the second aspect, the side of the movable partis attached to the conjugate pad by an adhesive substance.

In another embodiment of the second aspect, the lateral flow assaydevice further comprises: a set of one or more holes going through theconjugate pad and the membrane; and a set of one or more movable poles,each movable pole going through a hole in the set of holes, wherein, inthe first state of the lateral flow assay device, the set of movablepoles is connected to the conjugate pad and creates the removable gap bykeeping the conjugate pad and the membrane separate, and wherein, in thesecond state of the lateral flow assay device, the set of one or moremovable poles is moved to remove the removable gap and connect theconjugate pad and the membrane.

In another embodiment of the second aspect, the set of movable poles isconnected to the conjugate pad by an adhesive substance.

In another embodiment of the second aspect, wherein the removable gap isa first removable gap, and wherein the membrane is a first membrane, thelateral flow assay device further comprises: a second membranecomprising a control line for determining whether the lateral flow assaydevice has successfully analyzed the fluid, wherein, in a third state ofthe lateral flow assay device, the lateral flow assay device isconfigured with a second removable gap between the first membrane andthe second membrane, the second removable gap substantially filled withair and preventing the fluid from flowing from the first membrane andthe test line into the second membrane and the control line, and whereinin a fourth state of the lateral flow assay device, the second removablegap is removed from between the first membrane and the second membranecausing the first membrane to be connected to the second membrane andallowing the fluid to flow from the first membrane and the test lineinto the second membrane and the control line by capillary action.

In another embodiment of the second aspect, the lateral flow assaydevice further comprises: a housing covering at least a portion of theconjugate pad and the first and second membranes, wherein the housingcomprises a movable section comprising a side attached to at least aportion of the second membrane, wherein, in the third state of thelateral flow assay device, the movable section creates the secondremovable gap by keeping the second membrane and the first membraneseparate, and wherein, in the fourth state of the lateral flow assaydevice, the movable section pushes the second membrane towards the firstmembrane causing the second membrane and the first membrane to connectto each other.

In another embodiment of the second aspect, the lateral flow assaydevice further comprises: a set of one or more holes going through thefirst and second membranes; and a set of one or more movable poles, eachmovable pole going through a hole in the set of holes, wherein, in thethird state of the lateral flow assay device, the set of movable polesis connected to the second membrane and creates the second removable gapby keeping the first and second membranes separate, and wherein, in thefourth state of the lateral flow assay device, the set of one or moremovable poles is moved to remove the second removable gap and connectthe first and second membranes.

In another embodiment of the second aspect, the lateral flow assaydevice further comprises: a wicking pad, wherein, in a fifth state ofthe lateral flow assay device, the lateral flow assay device isconfigured with a third removable gap between the wicking pad and thesecond membrane, the third removable gap substantially filled with airand preventing the fluid from flowing from the second membrane and thecontrol line into the wicking pad, and wherein, in a sixth state of thelateral flow assay device, the third gap is removed from between thesecond membrane and the wicking pad causing the second membrane to beconnected to the wicking pad and allowing the fluid to flow from thesecond membrane and the control line into the wicking pad by capillaryaction.

In another embodiment of the second aspect, the lateral flow assaydevice further comprises: a housing covering at least a portion of thesecond membrane and the wicking pad, wherein the housing comprises amovable section comprising a side attached to at least a portion of thewicking pad, wherein, in the fifth state of the lateral flow assaydevice, the movable section creates the third removable gap by keepingthe wicking pad separate from the second membrane, and wherein, in thesixth state of the lateral flow assay device, the movable section pushesthe wicking pad towards the second membrane causing the wicking pad andthe second membrane to connect to each other.

In another embodiment of the second aspect, the lateral flow assaydevice further comprises: a set of one or more holes going through thesecond membrane and the wicking pad; and a set of one or more movablepoles, each removable pole going through a hole in the set of holes,wherein, in the fifth state of the lateral flow assay device, the set ofmovable poles is connected to the wicking pad and creating the thirdremovable gap by keeping the wicking pad and the second membraneseparate, and wherein, in the sixth state of the lateral flow assaydevice, the set of one or more movable poles is moved to remove thethird removable gap and connect the wicking pad and the second membrane.

In a third aspect, a lateral flow assay device, comprises: a sample padfor receiving a quantity of fluid; a conjugate pad fluidically connectedto the sample pad, wherein the sample pad is configured to transport thefluid to the conjugate pad by capillary action, wherein the conjugatepad contains an antibody for binding to the target analyte, and whereinthe target analyte and the antibody require a first time period to bind;a membrane comprising a test line for determining whether the fluidcomprises a target analyte; a removable physical barrier; at least afirst magnet connected to the removable physical barrier; a processingunit; and an electromagnet comprising a coil and a core, wherein thecore acts as a magnet when a current is passed through the coil, whereinthe core does not act as a magnet when no current is passed through thecoil, wherein the core is configured to stay at a specific distance fromthe first magnet at a beginning of an assay test, and wherein the coreis configured to attract the first magnet and pull the removablephysical barrier from between the conjugate pad and the membrane whenthe core acts as a magnet and the core is at the specific distance fromthe first magnet, wherein the removable physical barrier is configuredto stay between the conjugate pad and the membrane at the beginning ofthe assay test, preventing the fluid from flowing from the conjugate padinto the membrane, wherein the processing unit is configured to:disconnect the current from the coil prior to the beginning of the assaytest; and after the first time period from the beginning of the assaytest, connecting the current to the coil to cause the core to act as amagnet and pull the first magnet and the movable physical barrier frombetween the conjugate pad and the membrane, wherein, when the removablephysical barrier is pulled from between the conjugate pad and themembrane, the conjugate pad is connected to the membrane, allowing thefluid to flow from the conjugate pad into the membrane and the test lineby capillary action.

In an embodiment of the third aspect, the first time period is greaterthan a time that takes for the fluid to be transported by capillaryaction from the sample pad to the conjugate pad and from the conjugatepad to the membrane.

In a fourth aspect, a system for performing an assay test comprises: alateral flow assay device; an electromagnet; and a processing unit,wherein the lateral flow assay device comprises: a sample pad forreceiving a quantity of fluid; a conjugate pad fluidically connected tothe sample pad, wherein the sample pad is configured to transport thefluid to the conjugate pad by capillary action, wherein the conjugatepad contains an antibody for binding to the target analyte, and whereinthe target analyte and the antibody require a first time period to bind;a membrane comprising a test line for determining whether the fluidcomprises a target analyte; a removable physical barrier; and at least afirst magnet connected to the removable physical barrier; wherein theelectromagnet comprises a coil and a core, wherein the core acts as amagnet when a current is passed through the coil, wherein the core doesnot act as a magnet when no current is passed through the coil, whereinthe core is configured to stay at a specific distance from the firstmagnet at a beginning of the assay test, and wherein the core isconfigured to attract the first magnet and pull the removable physicalbarrier from between the conjugate pad and the membrane when the coreacts as a magnet and the core is at the specific distance from the firstmagnet; wherein the removable physical barrier is configured to staybetween the conjugate pad and the membrane at the beginning of the assaytest, preventing the fluid from flowing from the conjugate pad into themembrane, wherein the processing unit is configured to: disconnect thecurrent from the coil prior to the beginning of the assay test; andafter the first time period from the beginning of the assay test,connecting the current to the coil and causing the core to act as amagnet and pull the first magnet and the movable physical barrier frombetween the conjugate pad and the membrane, and wherein, when theremovable physical barrier is pulled from between the conjugate pad andthe membrane, the conjugate pad is connected to the membrane, allowingthe fluid to flow from the conjugate pad into the membrane and the testline by capillary action.

In an embodiment of the fourth aspect, the first time period is greaterthan a time that takes for the fluid to be transported by capillaryaction from the sample pad to the conjugate pad and from the conjugatepad to the membrane.

The above description presents the best mode contemplated for carryingout the present embodiments, and of the manner and process of practicingthem, in such full, clear, concise, and exact terms as to enable anyperson skilled in the art to which they pertain to practice theseembodiments. The present embodiments are, however, susceptible tomodifications and alternate constructions from those discussed abovethat are fully equivalent. Consequently, the present invention is notlimited to the particular embodiments disclosed. On the contrary, thepresent invention covers all modifications and alternate constructionscoming within the spirit and scope of the present disclosure. Forexample, the steps in the processes described herein need not beperformed in the same order as they have been presented and may beperformed in any order(s). Further, steps that have been presented asbeing performed separately may in alternative embodiments be performedconcurrently. Likewise, steps that have been presented as beingperformed concurrently may in alternative embodiments be performedseparately.

What is claimed is:
 1. A lateral flow assay device, comprising: aconjugate pad configured to receive a quantity of fluid after a start ofa test, the conjugate pad configured to move the fluid by capillaryaction; a membrane comprising a test line for determining whether thefluid comprises a target analyte, the membrane configured to move thefluid by capillary action; a backing connected to the conjugate pad; amagnet attached to the backing of the conjugate pad; an electromagnetconfigured to receive current in a first direction to repel the magnetand maintain a gap between the conjugate pad and the membrane prior tothe start of the test to prevent the conjugate pad and the membrane fromcontacting each other, the electromagnet configured to receive currentin a second direction to attract the magnet and remove the gap betweenthe conjugate pad and the membrane to connect the conjugate pad and themembrane to allow the fluid to flow from the conjugate pad to themembrane; and a processor configured to: receive a signal indicating thestart of the test; and generate one or more signals after the start ofthe test to change the direction of the current received by theelectromagnet a plurality of times, causing the electromagnet to attractand repel the magnet a plurality of times to control an amount of timethat the fluid travels across the membrane.
 2. The lateral flow assaydevice of claim 1, wherein the processor is configured to receive aconjugate time indicating an amount of time required for the fluid toremain on the conjugate pad prior to the conjugate pad making contactwith the membrane; and wherein the processor is configured to generatethe one or more signals to change the direction of the current receivedby the electromagnet after determining that the conjugate time haselapsed since the start of the test.
 3. The lateral flow assay device ofclaim 1, wherein the magnet is a first magnet, wherein the electromagnetis a first electromagnet, the lateral flow assay device furthercomprising: a wicking pad; a backing connected to the wicking pad; asecond magnet attached to the backing of the wicking pad; a secondelectromagnet configured to receive current in a first direction torepel the second magnet and maintain a gap between the wicking pad andthe membrane to prevent the wicking pad and the membrane from contactingeach other, the second electromagnet configured to receive current in asecond direction to attract the second magnet and remove the gap betweenthe wicking pad and the membrane to allow the fluid to flow from themembrane to the wicking pad, the processor configured to generate one ormore signals after the start of the test to change the direction of thecurrent received by the second electromagnet a plurality of times,causing the second electromagnet to attract and repel the second magneta plurality of times to control an amount of time that the fluid travelsfrom the membrane into the wicking pad.
 4. The lateral flow assay deviceof claim 1, wherein the processor is configured to: receive a value fora flow time indicating a time for the fluid to move across the membrane;determine, based on the value of the flow time, a duration for theconjugate pad and the membrane to have contact with each other, aduration for the conjugate pad and the membrane to have no contact witheach other, and a number of times to connect and disconnect theconjugate pad and the membrane; and generate said one or more signals tochange the direction of the electric current received by theelectromagnet by using the duration for the conjugate pad and themembrane to have contact with each other, the duration for the conjugatepad and the membrane to have no contact with each other, and the numberof times to connect and disconnect the conjugate pad and the membrane.5. The lateral flow assay device of claim 4, wherein the processor isconfigured to control a flow rate of the liquid across the membrane bychanging the duration for the conjugate pad and the membrane to havecontact with each other a plurality of times.
 6. The lateral flow assaydevice of claim 4, wherein the processor is configured to control a flowrate of the liquid across the membrane by changing the duration for theconjugate pad and the membrane to have no contact with each other aplurality of times.
 7. The lateral flow assay device of claim 4, whereinthe processor is configured to determine the duration for the conjugatepad and the membrane to have contact with each other, and the durationfor the conjugate pad and the membrane to have no contact with eachother by using experimental values stored in a one or more tables thatmap the duration for the conjugate pad and the membrane to have contactwith each other, and the duration for the conjugate pad and the membraneto have no contact with each other to a set of flow times.
 8. Thelateral flow assay device of claim 1, wherein the electromagnetcomprises an electromagnetically inductive coil wrapped around ametallic core, wherein the coil is configured to generate a magneticfield in a first direction when the electromagnet receive the current inthe first direction, and wherein the coil is configured to generate amagnetic field in a second direction when the electromagnet receive thecurrent in the second direction.
 9. The lateral flow assay device ofclaim 8, wherein said metallic core comprises one or more of iron,nickel, and cobalt.
 10. The lateral flow assay device of claim 1 furthercomprising a power source for generating said electric current.
 11. Alateral flow assay device, comprising: a conjugate pad configured toreceive a quantity of fluid after a start of a test, the conjugate padconfigured to move the fluid by capillary action; a membrane comprisinga test line for determining whether the fluid comprises a targetanalyte, the membrane configured to move the fluid by capillary action;a backing connected to the conjugate pad; a magnet attached to thebacking of the conjugate pad; an electromagnet configured to receivecurrent in a first direction to attract the magnet and maintain a gapbetween the conjugate pad and the membrane prior to the start of thetest to prevent the conjugate pad and the membrane from contacting eachother, the electromagnet configured to receive current in a seconddirection to repel the magnet and remove the gap between the conjugatepad and the membrane to connect the conjugate pad and the membrane andallow the fluid to flow from the conjugate pad to the membrane; and aprocessor configured to: receive a signal indicating the start of thetest; and generate one or more signals after the start of the test tochange the direction of the current received by the electromagnet aplurality of times, causing the electromagnet to repel and attract themagnet a plurality of times to control an amount of time that the fluidtravels across the membrane.
 12. The lateral flow assay device of claim11, wherein the processor configured to receive a conjugate timeindicating an amount of time required for the fluid to remain on theconjugate pad prior to the conjugate pad making contact with themembrane; and wherein the processor configured to generate the one ormore signals to change the direction of the current received by theelectromagnet after determining that the conjugate time has elapsedsince the start of the test.
 13. The lateral flow assay device of claim11, wherein the magnet is a first magnet, wherein the electromagnet is afirst electromagnet, the lateral flow assay device further comprising: awicking pad; a backing connected to the wicking pad; a second magnetattached to the backing of the wicking pad; a second electromagnetconfigured to receive current in a first direction to attract the secondmagnet and maintain a gap between the wicking pad and the membrane toprevent the wicking pad and the membrane from contacting each other, thesecond electromagnet configured to receive current in a second directionto repel the second magnet and remove the gap between the wicking padand the membrane to connect the membrane and the wicking pad to allowthe fluid to flow from the membrane to the wicking pad; wherein theprocessor is configured to generate one or more signals after the startof the test to change the direction of the current received by thesecond electromagnet, causing the second electromagnet to repel andattract the second magnet a plurality of times to control an amount oftime that the fluid travels from the membrane into the wicking pad. 14.The lateral flow assay device of claim 11, wherein the processor isconfigured to: receive a value for a flow time indicating a time for thefluid to move across the membrane; determine, based on the value of theflow time, a duration for the conjugate pad and the membrane to havecontact with each other, a duration for the conjugate pad and themembrane to have no contact with each other, and a number of times toconnect and disconnect the conjugate pad and the membrane; and generatesaid one or more signals to change the direction of the electric currentreceived by the electromagnet by using the duration for the conjugatepad and the membrane to have contact with each other, the duration forthe conjugate pad and the membrane to have no contact with each other,and the number of times to connect and disconnect the conjugate pad andthe membrane.
 15. The lateral flow assay device of claim 14, wherein theprocessor is configured to control a flow rate of the liquid across themembrane by changing the duration for the conjugate pad and the membraneto have contact with each other a plurality of times.
 16. The lateralflow assay device of claim 14, wherein the processor is configured tocontrol a flow rate of the liquid across the membrane by changing theduration for the conjugate pad and the membrane to have no contact witheach other a plurality of times.
 17. The lateral flow assay device ofclaim 14, wherein the processor is configured to determine the durationfor the conjugate pad and the membrane to have contact with each other,and the duration for the conjugate pad and the membrane to have nocontact with each other by using experimental values stored in a one ormore tables that map the duration for the conjugate pad and the membraneto have contact with each other, and the duration for the conjugate padand the membrane to have no contact with each other to a set of flowtimes.
 18. The lateral flow assay device of claim 11, wherein theelectromagnet comprises an electromagnetically inductive coil wrappedaround a metallic core, the coil configured to generate a magnetic fieldin a first direction when the electromagnet receive the current in thefirst direction, the coil configured to generate a magnetic field in asecond direction when the electromagnet receive the current in thesecond direction.
 19. The lateral flow assay device of claim 18, whereinsaid metallic core comprises one or more of iron, nickel, and cobalt.20. The lateral flow assay device of claim 11 further comprising a powersource for generating said electric current.